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Diffstat (limited to 'comm/mailnews/db/mork/mdb.h')
| -rw-r--r-- | comm/mailnews/db/mork/mdb.h | 2550 |
1 files changed, 2550 insertions, 0 deletions
diff --git a/comm/mailnews/db/mork/mdb.h b/comm/mailnews/db/mork/mdb.h new file mode 100644 index 0000000000..2f0f0d80e1 --- /dev/null +++ b/comm/mailnews/db/mork/mdb.h @@ -0,0 +1,2550 @@ +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* ***** BEGIN LICENSE BLOCK ***** + * Version: MPL 1.1/GPL 2.0/LGPL 2.1 + * + * The contents of this file are subject to the Mozilla Public License Version + * 1.1 (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * http://www.mozilla.org/MPL/ + * + * Software distributed under the License is distributed on an "AS IS" basis, + * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License + * for the specific language governing rights and limitations under the + * License. + * + * The Original Code is mozilla.org code. + * + * The Initial Developer of the Original Code is + * Netscape Communications Corporation. + * Portions created by the Initial Developer are Copyright (C) 1999 + * the Initial Developer. All Rights Reserved. + * + * Contributor(s): + * Blake Ross (blake@blakeross.com) + * + * Alternatively, the contents of this file may be used under the terms of + * either of the GNU General Public License Version 2 or later (the "GPL"), + * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"), + * in which case the provisions of the GPL or the LGPL are applicable instead + * of those above. If you wish to allow use of your version of this file only + * under the terms of either the GPL or the LGPL, and not to allow others to + * use your version of this file under the terms of the MPL, indicate your + * decision by deleting the provisions above and replace them with the notice + * and other provisions required by the GPL or the LGPL. If you do not delete + * the provisions above, a recipient may use your version of this file under + * the terms of any one of the MPL, the GPL or the LGPL. + * + * ***** END LICENSE BLOCK ***** */ + +#ifndef _MDB_ +#define _MDB_ 1 + +#include "mozilla/Path.h" +#include "nscore.h" +#include "nsISupports.h" +// 456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789 + +// { %%%%% begin scalar typedefs %%%%% +typedef unsigned char mdb_u1; // make sure this is one byte +typedef unsigned short mdb_u2; // make sure this is two bytes +typedef short mdb_i2; // make sure this is two bytes +typedef uint32_t mdb_u4; // make sure this is four bytes +typedef int32_t mdb_i4; // make sure this is four bytes +typedef PRWord mdb_ip; // make sure sizeof(mdb_ip) == sizeof(void*) + +typedef mdb_u1 mdb_bool; // unsigned byte with zero=false, nonzero=true + +/* canonical boolean constants provided only for code clarity: */ +#define mdbBool_kTrue ((mdb_bool)1) /* actually any nonzero means true */ +#define mdbBool_kFalse ((mdb_bool)0) /* only zero means false */ + +typedef mdb_u4 mdb_id; // unsigned object identity in a scope +typedef mdb_id mdb_rid; // unsigned row identity inside scope +typedef mdb_id mdb_tid; // unsigned table identity inside scope +typedef mdb_u4 mdb_token; // unsigned token for atomized string +typedef mdb_token mdb_scope; // token used to id scope for rows +typedef mdb_token mdb_kind; // token used to id kind for tables +typedef mdb_token mdb_column; // token used to id columns for rows +typedef mdb_token mdb_cscode; // token used to id charset names +typedef mdb_u4 mdb_seed; // unsigned collection change counter +typedef mdb_u4 mdb_count; // unsigned collection member count +typedef mdb_u4 mdb_size; // unsigned physical media size +typedef mdb_u4 mdb_fill; // unsigned logical content size +typedef mdb_u4 mdb_more; // more available bytes for larger buffer + +typedef mdb_u2 mork_uses; // 2-byte strong uses count +typedef mdb_u2 mork_refs; // 2-byte actual reference count + +#define mdbId_kNone ((mdb_id)-1) /* never a valid Mork object ID */ + +typedef mdb_u4 mdb_percent; // 0..100, with values >100 same as 100 + +typedef mdb_u1 mdb_priority; // 0..9, for a total of ten different values + +// sequence position is signed; negative is useful to mean "before first": +typedef mdb_i4 mdb_pos; // signed zero-based ordinal collection position + +#define mdbPos_kBeforeFirst ((mdb_pos)-1) /* any negative is before zero */ + +// order is also signed, so we can use three states for comparison order: +typedef mdb_i4 mdb_order; // neg:lessthan, zero:equalto, pos:greaterthan + +typedef mdb_order (*mdbAny_Order)(const void* inA, const void* inB, + const void* inClosure); + +// } %%%%% end scalar typedefs %%%%% + +// { %%%%% begin C structs %%%%% + +#ifndef mdbScopeStringSet_typedef +typedef struct mdbScopeStringSet mdbScopeStringSet; +# define mdbScopeStringSet_typedef 1 +#endif + +/*| mdbScopeStringSet: a set of null-terminated C strings that enumerate some +**| names of row scopes, so that row scopes intended for use by an application +**| can be declared by an app when trying to open or create a database file. +**| (We use strings and not tokens because we cannot know the tokens for any +**| particular db without having first opened the db.) The goal is to inform +**| a db runtime that scopes not appearing in this list can be given relatively +**| short shrift in runtime representation, with the expectation that other +**| scopes will not actually be used. However, a db should still be prepared +**| to handle accessing row scopes not in this list, rather than raising errors. +**| But it could be quite expensive to access a row scope not on the list. +**| Note a zero count for the string set means no such string set is being +**| specified, and that a db should handle all row scopes efficiently. +**| (It does NOT mean an app plans to use no content whatsoever.) +|*/ +#ifndef mdbScopeStringSet_struct +# define mdbScopeStringSet_struct 1 +struct mdbScopeStringSet { // vector of scopes for use in db opening policy + // when mScopeStringSet_Count is zero, this means no scope constraints + mdb_count mScopeStringSet_Count; // number of strings in vector below + const char** mScopeStringSet_Strings; // null-ended ascii scope strings +}; +#endif /*mdbScopeStringSet_struct*/ + +#ifndef mdbOpenPolicy_typedef +typedef struct mdbOpenPolicy mdbOpenPolicy; +# define mdbOpenPolicy_typedef 1 +#endif + +#ifndef mdbOpenPolicy_struct +# define mdbOpenPolicy_struct 1 +struct mdbOpenPolicy { // policies affecting db usage for ports and stores + mdbScopeStringSet mOpenPolicy_ScopePlan; // predeclare scope usage plan + mdb_bool mOpenPolicy_MaxLazy; // nonzero: do least work + mdb_bool mOpenPolicy_MinMemory; // nonzero: use least memory +}; +#endif /*mdbOpenPolicy_struct*/ + +#ifndef mdbTokenSet_typedef +typedef struct mdbTokenSet mdbTokenSet; +# define mdbTokenSet_typedef 1 +#endif + +#ifndef mdbTokenSet_struct +# define mdbTokenSet_struct 1 +struct mdbTokenSet { // array for a set of tokens, and actual slots used + mdb_count mTokenSet_Count; // number of token slots in the array + mdb_fill mTokenSet_Fill; // the subset of count slots actually used + mdb_more mTokenSet_More; // more tokens available for bigger array + mdb_token* mTokenSet_Tokens; // array of count mdb_token instances +}; +#endif /*mdbTokenSet_struct*/ + +#ifndef mdbUsagePolicy_typedef +typedef struct mdbUsagePolicy mdbUsagePolicy; +# define mdbUsagePolicy_typedef 1 +#endif + +/*| mdbUsagePolicy: another version of mdbOpenPolicy which uses tokens instead +**| of scope strings, because usage policies can be constructed for use with a +**| db that is already open, while an open policy must be constructed before a +**| db has yet been opened. +|*/ +#ifndef mdbUsagePolicy_struct +# define mdbUsagePolicy_struct 1 +struct mdbUsagePolicy { // policies affecting db usage for ports and stores + mdbTokenSet mUsagePolicy_ScopePlan; // current scope usage plan + mdb_bool mUsagePolicy_MaxLazy; // nonzero: do least work + mdb_bool mUsagePolicy_MinMemory; // nonzero: use least memory +}; +#endif /*mdbUsagePolicy_struct*/ + +#ifndef mdbOid_typedef +typedef struct mdbOid mdbOid; +# define mdbOid_typedef 1 +#endif + +#ifndef mdbOid_struct +# define mdbOid_struct 1 +struct mdbOid { // identity of some row or table inside a database + mdb_scope mOid_Scope; // scope token for an id's namespace + mdb_id mOid_Id; // identity of object inside scope namespace +}; +#endif /*mdbOid_struct*/ + +#ifndef mdbRange_typedef +typedef struct mdbRange mdbRange; +# define mdbRange_typedef 1 +#endif + +#ifndef mdbRange_struct +# define mdbRange_struct 1 +struct mdbRange { // range of row positions in a table + mdb_pos mRange_FirstPos; // position of first row + mdb_pos mRange_LastPos; // position of last row +}; +#endif /*mdbRange_struct*/ + +#ifndef mdbColumnSet_typedef +typedef struct mdbColumnSet mdbColumnSet; +# define mdbColumnSet_typedef 1 +#endif + +#ifndef mdbColumnSet_struct +# define mdbColumnSet_struct 1 +struct mdbColumnSet { // array of column tokens (just the same as mdbTokenSet) + mdb_count mColumnSet_Count; // number of columns + mdb_column* mColumnSet_Columns; // count mdb_column instances +}; +#endif /*mdbColumnSet_struct*/ + +#ifndef mdbYarn_typedef +typedef struct mdbYarn mdbYarn; +# define mdbYarn_typedef 1 +#endif + +#ifdef MDB_BEGIN_C_LINKAGE_define +# define MDB_BEGIN_C_LINKAGE_define 1 +# define MDB_BEGIN_C_LINKAGE extern "C" { +# define MDB_END_C_LINKAGE } +#endif /*MDB_BEGIN_C_LINKAGE_define*/ + +/*| mdbYarn_mGrow: an abstract API for growing the size of a mdbYarn +**| instance. With respect to a specific API that requires a caller +**| to supply a string (mdbYarn) that a callee fills with content +**| that might exceed the specified size, mdbYarn_mGrow is a caller- +**| supplied means of letting a callee attempt to increase the string +**| size to become large enough to receive all content available. +**| +**|| Grow(): a method for requesting that a yarn instance be made +**| larger in size. Note that such requests need not be honored, and +**| need not be honored in full if only partial size growth is desired. +**| (Note that no nsIMdbEnv instance is passed as argument, although one +**| might be needed in some circumstances. So if an nsIMdbEnv is needed, +**| a reference to one might be held inside a mdbYarn member slot.) +**| +**|| self: a yarn instance to be grown. Presumably this yarn is +**| the instance which holds the mYarn_Grow method pointer. Yarn +**| instancesshould only be passed to grow methods which they were +**| specifically designed to fit, as indicated by the mYarn_Grow slot. +**| +**|| inNewSize: the new desired value for slot mYarn_Size in self. +**| If mYarn_Size is already this big, then nothing should be done. +**| If inNewSize is larger than seems feasible or desirable to honor, +**| then any size restriction policy can be used to grow to some size +**| greater than mYarn_Size. (Grow() might even grow to a size +**| greater than inNewSize in order to make the increase in size seem +**| worthwhile, rather than growing in many smaller steps over time.) +|*/ +typedef void (*mdbYarn_mGrow)(mdbYarn* self, mdb_size inNewSize); +// mdbYarn_mGrow methods must be declared with C linkage in C++ + +/*| mdbYarn: a variable length "string" of arbitrary binary bytes, +**| whose length is mYarn_Fill, inside a buffer mYarn_Buf that has +**| at most mYarn_Size byte of physical space. +**| +**|| mYarn_Buf: a pointer to space containing content. This slot +**| might never be nil when mYarn_Size is nonzero, but checks for nil +**| are recommended anyway. +**| (Implementations of mdbYarn_mGrow methods should take care to +**| ensure the existence of a replacement before dropping old Bufs.) +**| Content in Buf can be anything in any format, but the mYarn_Form +**| implies the actual format by some caller-to-callee convention. +**| mYarn_Form==0 implies US-ASCII iso-8859-1 Latin1 string content. +**| +**|| mYarn_Size: the physical size of Buf in bytes. Note that if one +**| intends to terminate a string with a null byte, that it must not +**| be written at or after mYarn_Buf[mYarn_Size] because this is after +**| the last byte in the physical buffer space. Size can be zero, +**| which means the string has no content whatsoever; note that when +**| Size is zero, this is a suitable reason for Buf==nil as well. +**| +**|| mYarn_Fill: the logical content in Buf in bytes, where Fill must +**| never exceed mYarn_Size. Note that yarn strings might not have a +**| terminating null byte (since they might not even be C strings), but +**| when they do, such terminating nulls are considered part of content +**| and therefore Fill will count such null bytes. So an "empty" C +**| string will have Fill==1, because content includes one null byte. +**| Fill does not mean "length" when applied to C strings for this +**| reason. However, clients using yarns to hold C strings can infer +**| that length is equal to Fill-1 (but should take care to handle the +**| case where Fill==0). To be paranoid, one can always copy to a +**| destination with size exceeding Fill, and place a redundant null +**| byte in the Fill position when this simplifies matters. +**| +**|| mYarn_Form: a designation of content format within mYarn_Buf. +**| The semantics of this slot are the least well defined, since the +**| actual meaning is context dependent, to the extent that callers +**| and callees must agree on format encoding conventions when such +**| are not standardized in many computing contexts. However, in the +**| context of a specific mdb database, mYarn_Form is a token for an +**| atomized string in that database that typically names a preferred +**| mime type charset designation. If and when mdbYarn is used for +**| other purposes away from the mdb interface, folks can use another +**| convention system for encoding content formats. However, in all +**| contexts is it useful to maintain the convention that Form==0 +**| implies Buf contains US-ASCII iso-8859-1 Latin1 string content. +**| +**|| mYarn_Grow: either a mdbYarn_mGrow method, or else nil. When +**| a mdbYarn_mGrow method is provided, this method can be used to +**| request a yarn buf size increase. A caller who constructs the +**| original mdbYarn instance decides whether a grow method is necessary +**| or desirable, and uses only grow methods suitable for the buffering +**| nature of a specific mdbYarn instance. (For example, Buf might be a +**| statically allocated string space which switches to something heap-based +**| when grown, and subsequent calls to grow the yarn must distinguish the +**| original static string from heap allocated space, etc.) Note that the +**| method stored in mYarn_Grow can change, and this might be a common way +**| to track memory managent changes in policy for mYarn_Buf. +|*/ +#ifndef mdbYarn_struct +# define mdbYarn_struct 1 +struct mdbYarn { // buffer with caller space allocation semantics + void* mYarn_Buf; // space for holding any binary content + mdb_fill mYarn_Fill; // logical content in Buf in bytes + mdb_size mYarn_Size; // physical size of Buf in bytes + mdb_more mYarn_More; // more available bytes if Buf is bigger + mdb_cscode mYarn_Form; // charset format encoding + mdbYarn_mGrow mYarn_Grow; // optional method to grow mYarn_Buf + + // Subclasses might add further slots after mYarn_Grow in order to + // maintain bookkeeping needs, such as state info about mYarn_Buf. +}; +#endif /*mdbYarn_struct*/ + +// } %%%%% end C structs %%%%% + +// { %%%%% begin class forward defines %%%%% +class nsIMdbEnv; +class nsIMdbObject; +class nsIMdbErrorHook; +class nsIMdbThumb; +class nsIMdbFactory; +class nsIMdbFile; +class nsIMdbPort; +class nsIMdbStore; +class nsIMdbCursor; +class nsIMdbPortTableCursor; +class nsIMdbCollection; +class nsIMdbTable; +class nsIMdbTableRowCursor; +class nsIMdbRow; +class nsIMdbRowCellCursor; +class nsIMdbBlob; +class nsIMdbCell; +class nsIMdbSorting; +// } %%%%% end class forward defines %%%%% + +// { %%%%% begin C++ abstract class interfaces %%%%% + +/*| nsIMdbObject: base class for all message db class interfaces +**| +**|| factory: all nsIMdbObjects from the same code suite have the same factory +**| +**|| refcounting: both strong and weak references, to ensure strong refs are +**| acyclic, while weak refs can cause cycles. CloseMdbObject() is +**| called when (strong) use counts hit zero, but clients can call this close +**| method early for some reason, if absolutely necessary even though it will +**| thwart the other uses of the same object. Note that implementations must +**| cope with close methods being called arbitrary numbers of times. The COM +**| calls to AddRef() and release ref map directly to strong use ref calls, +**| but the total ref count for COM objects is the sum of weak & strong refs. +|*/ + +#define NS_IMDBOBJECT_IID_STR "5533ea4b-14c3-4bef-ac60-22f9e9a49084" + +#define NS_IMDBOBJECT_IID \ + { \ + 0x5533ea4b, 0x14c3, 0x4bef, { \ + 0xac, 0x60, 0x22, 0xf9, 0xe9, 0xa4, 0x90, 0x84 \ + } \ + } + +class nsIMdbObject : public nsISupports { // msg db base class + public: + NS_DECLARE_STATIC_IID_ACCESSOR(NS_IMDBOBJECT_IID) + // { ===== begin nsIMdbObject methods ===== + + // { ----- begin attribute methods ----- + NS_IMETHOD IsFrozenMdbObject(nsIMdbEnv* ev, mdb_bool* outIsReadonly) = 0; + // same as nsIMdbPort::GetIsPortReadonly() when this object is inside a port. + // } ----- end attribute methods ----- + + // { ----- begin factory methods ----- + NS_IMETHOD GetMdbFactory(nsIMdbEnv* ev, nsIMdbFactory** acqFactory) = 0; + // } ----- end factory methods ----- + + // { ----- begin ref counting for well-behaved cyclic graphs ----- + NS_IMETHOD GetWeakRefCount(nsIMdbEnv* ev, // weak refs + mdb_count* outCount) = 0; + NS_IMETHOD GetStrongRefCount(nsIMdbEnv* ev, // strong refs + mdb_count* outCount) = 0; + + NS_IMETHOD AddWeakRef(nsIMdbEnv* ev) = 0; + NS_IMETHOD_(mork_uses) AddStrongRef(nsIMdbEnv* ev) = 0; + + NS_IMETHOD CutWeakRef(nsIMdbEnv* ev) = 0; + NS_IMETHOD CutStrongRef(nsIMdbEnv* ev) = 0; + + NS_IMETHOD CloseMdbObject(nsIMdbEnv* ev) = 0; // called at strong refs zero + NS_IMETHOD IsOpenMdbObject(nsIMdbEnv* ev, mdb_bool* outOpen) = 0; + // } ----- end ref counting ----- + + // } ===== end nsIMdbObject methods ===== +}; + +NS_DEFINE_STATIC_IID_ACCESSOR(nsIMdbObject, NS_IMDBOBJECT_IID) + +/*| nsIMdbErrorHook: a base class for clients of this API to subclass, in order +**| to provide a callback installable in nsIMdbEnv for error notifications. If +**| apps that subclass nsIMdbErrorHook wish to maintain a reference to the env +**| that contains the hook, then this should be a weak ref to avoid cycles. +**| +**|| OnError: when nsIMdbEnv has an error condition that causes the total count +**| of errors to increase, then nsIMdbEnv should call OnError() to report the +**| error in some fashion when an instance of nsIMdbErrorHook is installed. The +**| variety of string flavors is currently due to the uncertainty here in the +**| nsIMdbBlob and nsIMdbCell interfaces. (Note that overloading by using the +**| same method name is not necessary here, and potentially less clear.) +|*/ +class nsIMdbErrorHook + : public nsISupports { // env callback handler to report errors + public: + // { ===== begin error methods ===== + NS_IMETHOD OnErrorString(nsIMdbEnv* ev, const char* inAscii) = 0; + NS_IMETHOD OnErrorYarn(nsIMdbEnv* ev, const mdbYarn* inYarn) = 0; + // } ===== end error methods ===== + + // { ===== begin warning methods ===== + NS_IMETHOD OnWarningString(nsIMdbEnv* ev, const char* inAscii) = 0; + NS_IMETHOD OnWarningYarn(nsIMdbEnv* ev, const mdbYarn* inYarn) = 0; + // } ===== end warning methods ===== + + // { ===== begin abort hint methods ===== + NS_IMETHOD OnAbortHintString(nsIMdbEnv* ev, const char* inAscii) = 0; + NS_IMETHOD OnAbortHintYarn(nsIMdbEnv* ev, const mdbYarn* inYarn) = 0; + // } ===== end abort hint methods ===== +}; + +/*| nsIMdbHeap: abstract memory allocation interface. +**| +**|| Alloc: return a block at least inSize bytes in size with alignment +**| suitable for any native type (such as long integers). When no such +**| block can be allocated, failure is indicated by a null address in +**| addition to reporting an error in the environment. +**| +**|| Free: deallocate a block allocated or resized earlier by the same +**| heap instance. If the inBlock parameter is nil, the heap should do +**| nothing (and crashing is strongly discouraged). +|*/ +class nsIMdbHeap { // caller-supplied memory management interface + public: + // { ===== begin nsIMdbHeap methods ===== + NS_IMETHOD Alloc(nsIMdbEnv* ev, // allocate a piece of memory + mdb_size inSize, // requested byte size of new memory block + void** outBlock) = + 0; // memory block of inSize bytes, or nil + + NS_IMETHOD Free(nsIMdbEnv* ev, // free block from Alloc or Resize() + void* ioBlock) = 0; // block to be destroyed/deallocated + + virtual size_t GetUsedSize() = 0; + + virtual ~nsIMdbHeap(){}; + // } ===== end nsIMdbHeap methods ===== +}; + +/*| nsIMdbCPlusHeap: Alloc() with global ::new(), Free() with global ::delete(). +**| Resize() is done by ::new() followed by ::delete(). +|*/ +class nsIMdbCPlusHeap { // caller-supplied memory management interface + public: + // { ===== begin nsIMdbHeap methods ===== + NS_IMETHOD Alloc(nsIMdbEnv* ev, // allocate a piece of memory + mdb_size inSize, // requested size of new memory block + void** outBlock); // memory block of inSize bytes, or nil + + NS_IMETHOD Free(nsIMdbEnv* ev, // free block allocated earlier by Alloc() + void* inBlock); + + NS_IMETHOD HeapAddStrongRef(nsIMdbEnv* ev); + NS_IMETHOD HeapCutStrongRef(nsIMdbEnv* ev); + // } ===== end nsIMdbHeap methods ===== +}; + +/*| nsIMdbThumb: +|*/ + +#define NS_IMDBTHUMB_IID_STR "6d3ad7c1-a809-4e74-8577-49fa9a4562fa" + +#define NS_IMDBTHUMB_IID \ + { \ + 0x6d3ad7c1, 0xa809, 0x4e74, { \ + 0x85, 0x77, 0x49, 0xfa, 0x9a, 0x45, 0x62, 0xfa \ + } \ + } + +class nsIMdbThumb + : public nsISupports { // closure for repeating incremental method + public: + NS_DECLARE_STATIC_IID_ACCESSOR(NS_IMDBTHUMB_IID) + + // { ===== begin nsIMdbThumb methods ===== + NS_IMETHOD GetProgress( + nsIMdbEnv* ev, + mdb_count* outTotal, // total somethings to do in operation + mdb_count* outCurrent, // subportion of total completed so far + mdb_bool* outDone, // is operation finished? + mdb_bool* outBroken // is operation irreparably dead and broken? + ) = 0; + + NS_IMETHOD DoMore( + nsIMdbEnv* ev, + mdb_count* outTotal, // total somethings to do in operation + mdb_count* outCurrent, // subportion of total completed so far + mdb_bool* outDone, // is operation finished? + mdb_bool* outBroken // is operation irreparably dead and broken? + ) = 0; + + NS_IMETHOD CancelAndBreakThumb( // cancel pending operation + nsIMdbEnv* ev) = 0; + // } ===== end nsIMdbThumb methods ===== +}; + +NS_DEFINE_STATIC_IID_ACCESSOR(nsIMdbThumb, NS_IMDBTHUMB_IID) + +/*| nsIMdbEnv: a context parameter used when calling most abstract db methods. +**| The main purpose of such an object is to permit a database implementation +**| to avoid the use of globals to share information between various parts of +**| the implementation behind the abstract db interface. An environment acts +**| like a session object for a given calling thread, and callers should use +**| at least one different nsIMdbEnv instance for each thread calling the API. +**| While the database implementation might not be threaded, it is highly +**| desirable that the db be thread-safe if calling threads use distinct +**| instances of nsIMdbEnv. Callers can stop at one nsIMdbEnv per thread, or +they +**| might decide to make on nsIMdbEnv instance for every nsIMdbPort opened, so +that +**| error information is segregated by database instance. Callers create +**| instances of nsIMdbEnv by calling the MakeEnv() method in nsIMdbFactory. +**| +**|| tracing: an environment might support some kind of tracing, and this +**| boolean attribute permits such activity to be enabled or disabled. +**| +**|| errors: when a call to the abstract db interface returns, a caller might +**| check the number of outstanding errors to see whether the operation did +**| actually succeed. Each nsIMdbEnv should have all its errors cleared by a +**| call to ClearErrors() before making each call to the abstract db API, +**| because outstanding errors might disable further database actions. (This +**| is not done inside the db interface, because the db cannot in general know +**| when a call originates from inside or outside -- only the app knows this.) +**| +**|| error hook: callers can install an instance of nsIMdbErrorHook to receive +**| error notifications whenever the error count increases. The hook can +**| be uninstalled by passing a null pointer. +**| +|*/ + +#define NS_IMDBENV_IID_STR "a765e46b-efb6-41e6-b75b-c5d6bd710594" + +#define NS_IMDBENV_IID \ + { \ + 0xa765e46b, 0xefb6, 0x41e6, { \ + 0xb7, 0x5b, 0xc5, 0xd6, 0xbd, 0x71, 0x05, 0x94 \ + } \ + } + +class nsIMdbEnv : public nsISupports { // db specific context parameter + public: + NS_DECLARE_STATIC_IID_ACCESSOR(NS_IMDBENV_IID) + // { ===== begin nsIMdbEnv methods ===== + + // { ----- begin attribute methods ----- + NS_IMETHOD GetErrorCount(mdb_count* outCount, mdb_bool* outShouldAbort) = 0; + NS_IMETHOD GetWarningCount(mdb_count* outCount, mdb_bool* outShouldAbort) = 0; + + NS_IMETHOD GetEnvBeVerbose(mdb_bool* outBeVerbose) = 0; + NS_IMETHOD SetEnvBeVerbose(mdb_bool inBeVerbose) = 0; + + NS_IMETHOD GetDoTrace(mdb_bool* outDoTrace) = 0; + NS_IMETHOD SetDoTrace(mdb_bool inDoTrace) = 0; + + NS_IMETHOD GetAutoClear(mdb_bool* outAutoClear) = 0; + NS_IMETHOD SetAutoClear(mdb_bool inAutoClear) = 0; + + NS_IMETHOD GetErrorHook(nsIMdbErrorHook** acqErrorHook) = 0; + NS_IMETHOD SetErrorHook(nsIMdbErrorHook* ioErrorHook) = + 0; // becomes referenced + + NS_IMETHOD GetHeap(nsIMdbHeap** acqHeap) = 0; + NS_IMETHOD SetHeap(nsIMdbHeap* ioHeap) = 0; // becomes referenced + // } ----- end attribute methods ----- + + NS_IMETHOD ClearErrors() = 0; // clear errors beore re-entering db API + NS_IMETHOD ClearWarnings() = 0; // clear warnings + NS_IMETHOD ClearErrorsAndWarnings() = 0; // clear both errors & warnings + // } ===== end nsIMdbEnv methods ===== +}; + +NS_DEFINE_STATIC_IID_ACCESSOR(nsIMdbEnv, NS_IMDBENV_IID) + +/*| nsIMdbFactory: the main entry points to the abstract db interface. A DLL +**| that supports this mdb interface need only have a single exported method +**| that will return an instance of nsIMdbFactory, so that further methods in +**| the suite can be accessed from objects returned by nsIMdbFactory methods. +**| +**|| mdbYarn: note all nsIMdbFactory subclasses must guarantee null +**| termination of all strings written into mdbYarn instances, as long as +**| mYarn_Size and mYarn_Buf are nonzero. Even truncated string values must +**| be null terminated. This is more strict behavior than mdbYarn requires, +**| but it is part of the nsIMdbFactory interface. +**| +**|| envs: an environment instance is required as per-thread context for +**| most of the db method calls, so nsIMdbFactory creates such instances. +**| +**|| rows: callers must be able to create row instances that are independent +**| of storage space that is part of the db content graph. Many interfaces +**| for data exchange have strictly copy semantics, so that a row instance +**| has no specific identity inside the db content model, and the text in +**| cells are an independenty copy of unexposed content inside the db model. +**| Callers are expected to maintain one or more row instances as a buffer +**| for staging cell content copied into or out of a table inside the db. +**| Callers are urged to use an instance of nsIMdbRow created by the +nsIMdbFactory +**| code suite, because reading and writing might be much more efficient than +**| when using a hand-rolled nsIMdbRow subclass with no relation to the suite. +**| +**|| ports: a port is a readonly interface to a specific database file. Most +**| of the methods to access a db file are suitable for a readonly interface, +**| so a port is the basic minimum for accessing content. This makes it +**| possible to read other external formats for import purposes, without +**| needing the code or competence necessary to write every such format. So +**| we can write generic import code just once, as long as every format can +**| show a face based on nsIMdbPort. (However, same suite import can be faster.) +**| Given a file name and the first 512 bytes of a file, a factory can say if +**| a port can be opened by this factory. Presumably an app maintains chains +**| of factories for different suites, and asks each in turn about opening a +**| a prospective file for reading (as a port) or writing (as a store). I'm +**| not ready to tackle issues of format fidelity and factory chain ordering. +**| +**|| stores: a store is a mutable interface to a specific database file, and +**| includes the port interface plus any methods particular to writing, which +**| are few in number. Presumably the set of files that can be opened as +**| stores is a subset of the set of files that can be opened as ports. A +**| new store can be created with CreateNewFileStore() by supplying a new +**| file name which does not yet exist (callers are always responsible for +**| destroying any existing files before calling this method). +|*/ + +#define NS_IMDBFACTORY_IID_STR "2b80395c-b91e-4990-b1a7-023e99ab14e9" + +#define NS_IMDBFACTORY_IID \ + { \ + 0xf04aa4ab, 0x1fe, 0x4115, { \ + 0xa4, 0xa5, 0x68, 0x19, 0xdf, 0xf1, 0x10, 0x3d \ + } \ + } + +class nsIMdbFactory : public nsISupports { // suite entry points + using PathChar = mozilla::filesystem::Path::value_type; + + public: + NS_DECLARE_STATIC_IID_ACCESSOR(NS_IMDBFACTORY_IID) + // { ===== begin nsIMdbFactory methods ===== + + // { ----- begin file methods ----- + NS_IMETHOD OpenOldFile(nsIMdbEnv* ev, nsIMdbHeap* ioHeap, + const PathChar* inFilePath, mdb_bool inFrozen, + nsIMdbFile** acqFile) = 0; + // Choose some subclass of nsIMdbFile to instantiate, in order to read + // (and write if not frozen) the file known by inFilePath. The file + // returned should be open and ready for use, and presumably positioned + // at the first byte position of the file. The exact manner in which + // files must be opened is considered a subclass specific detail, and + // other portions or Mork source code don't want to know how it's done. + + NS_IMETHOD CreateNewFile(nsIMdbEnv* ev, nsIMdbHeap* ioHeap, + const PathChar* inFilePath, + nsIMdbFile** acqFile) = 0; + // Choose some subclass of nsIMdbFile to instantiate, in order to read + // (and write if not frozen) the file known by inFilePath. The file + // returned should be created and ready for use, and presumably positioned + // at the first byte position of the file. The exact manner in which + // files must be opened is considered a subclass specific detail, and + // other portions or Mork source code don't want to know how it's done. + // } ----- end file methods ----- + + // { ----- begin env methods ----- + NS_IMETHOD MakeEnv(nsIMdbHeap* ioHeap, + nsIMdbEnv** acqEnv) = 0; // acquire new env + // ioHeap can be nil, causing a MakeHeap() style heap instance to be used + // } ----- end env methods ----- + + // { ----- begin heap methods ----- + NS_IMETHOD MakeHeap(nsIMdbEnv* ev, + nsIMdbHeap** acqHeap) = 0; // acquire new heap + // } ----- end heap methods ----- + + // { ----- begin row methods ----- + NS_IMETHOD MakeRow(nsIMdbEnv* ev, nsIMdbHeap* ioHeap, + nsIMdbRow** acqRow) = 0; // new row + // ioHeap can be nil, causing the heap associated with ev to be used + // } ----- end row methods ----- + + // { ----- begin port methods ----- + NS_IMETHOD CanOpenFilePort( + nsIMdbEnv* ev, // context + // const char* inFilePath, // the file to investigate + // const mdbYarn* inFirst512Bytes, + nsIMdbFile* ioFile, // db abstract file interface + mdb_bool* outCanOpen, // whether OpenFilePort() might succeed + mdbYarn* outFormatVersion) = 0; // informal file format description + + NS_IMETHOD OpenFilePort( + nsIMdbEnv* ev, // context + nsIMdbHeap* ioHeap, // can be nil to cause ev's heap attribute to be used + // const char* inFilePath, // the file to open for readonly import + nsIMdbFile* ioFile, // db abstract file interface + const mdbOpenPolicy* inOpenPolicy, // runtime policies for using db + nsIMdbThumb** acqThumb) = 0; // acquire thumb for incremental port open + // Call nsIMdbThumb::DoMore() until done, or until the thumb is broken, and + // then call nsIMdbFactory::ThumbToOpenPort() to get the port instance. + + NS_IMETHOD + ThumbToOpenPort( // redeeming a completed thumb from OpenFilePort() + nsIMdbEnv* ev, // context + nsIMdbThumb* ioThumb, // thumb from OpenFilePort() with done status + nsIMdbPort** acqPort) = 0; // acquire new port object + // } ----- end port methods ----- + + // { ----- begin store methods ----- + NS_IMETHOD CanOpenFileStore( + nsIMdbEnv* ev, // context + // const char* inFilePath, // the file to investigate + // const mdbYarn* inFirst512Bytes, + nsIMdbFile* ioFile, // db abstract file interface + mdb_bool* outCanOpenAsStore, // whether OpenFileStore() might succeed + mdb_bool* outCanOpenAsPort, // whether OpenFilePort() might succeed + mdbYarn* outFormatVersion) = 0; // informal file format description + + NS_IMETHOD OpenFileStore( // open an existing database + nsIMdbEnv* ev, // context + nsIMdbHeap* ioHeap, // can be nil to cause ev's heap attribute to be used + // const char* inFilePath, // the file to open for general db usage + nsIMdbFile* ioFile, // db abstract file interface + const mdbOpenPolicy* inOpenPolicy, // runtime policies for using db + nsIMdbThumb** acqThumb) = 0; // acquire thumb for incremental store open + // Call nsIMdbThumb::DoMore() until done, or until the thumb is broken, and + // then call nsIMdbFactory::ThumbToOpenStore() to get the store instance. + + NS_IMETHOD + ThumbToOpenStore( // redeem completed thumb from OpenFileStore() + nsIMdbEnv* ev, // context + nsIMdbThumb* ioThumb, // thumb from OpenFileStore() with done status + nsIMdbStore** acqStore) = 0; // acquire new db store object + + NS_IMETHOD CreateNewFileStore( // create a new db with minimal content + nsIMdbEnv* ev, // context + nsIMdbHeap* ioHeap, // can be nil to cause ev's heap attribute to be used + // const char* inFilePath, // name of file which should not yet exist + nsIMdbFile* ioFile, // db abstract file interface + const mdbOpenPolicy* inOpenPolicy, // runtime policies for using db + nsIMdbStore** acqStore) = 0; // acquire new db store object + // } ----- end store methods ----- + + // } ===== end nsIMdbFactory methods ===== +}; + +NS_DEFINE_STATIC_IID_ACCESSOR(nsIMdbFactory, NS_IMDBFACTORY_IID) + +extern "C" nsIMdbFactory* MakeMdbFactory(); + +/*| nsIMdbFile: abstract file interface resembling the original morkFile +**| abstract interface (which was in turn modeled on the file interface +**| from public domain IronDoc). The design of this file interface is +**| complicated by the fact that some DB's will not find this interface +**| adequate for all runtime requirements (even though this file API is +**| enough to implement text-based DB's like Mork). For this reason, +**| more methods have been added to let a DB library force the file to +**| become closed so the DB can reopen the file in some other manner. +**| Folks are encouraged to suggest ways to tune this interface to suit +**| DB's that cannot manage to pull their maneuvers even given this API. +**| +**|| Tell: get the current i/o position in file +**| +**|| Seek: change the current i/o position in file +**| +**|| Eof: return file's total length in bytes +**| +**|| Read: input inSize bytes into outBuf, returning actual transfer size +**| +**|| Get: read starting at specific file offset (e.g. Seek(); Read();) +**| +**|| Write: output inSize bytes from inBuf, returning actual transfer size +**| +**|| Put: write starting at specific file offset (e.g. Seek(); Write();) +**| +**|| Flush: if written bytes are buffered, push them to final destination +**| +**|| Path: get file path in some string representation. This is intended +**| either to support the display of file name in a user presentation, or +**| to support the closing and reopening of the file when the DB needs more +**| exotic file access than is presented by the nsIMdbFile interface. +**| +**|| Steal: tell this file to close any associated i/o stream in the file +**| system, because the file ioThief intends to reopen the file in order +**| to provide the MDB implementation with more exotic file access than is +**| offered by the nsIMdbFile alone. Presumably the thief knows enough +**| from Path() in order to know which file to reopen. If Steal() is +**| successful, this file should probably delegate all future calls to +**| the nsIMdbFile interface down to the thief files, so that even after +**| the file has been stolen, it can still be read, written, or forcibly +**| closed (by a call to CloseMdbObject()). +**| +**|| Thief: acquire and return thief passed to an earlier call to Steal(). +|*/ + +#define NS_IMDBFILE_IID_STR "f04aa4ab-1fe7-4115-a4a5-6819dff1103d" + +#define NS_IMDBFILE_IID \ + { \ + 0xf04aa4ab, 0x1fe, 0x4115, { \ + 0xa4, 0xa5, 0x68, 0x19, 0xdf, 0xf1, 0x10, 0x3d \ + } \ + } + +class nsIMdbFile : public nsISupports { // minimal file interface + public: + NS_DECLARE_STATIC_IID_ACCESSOR(NS_IMDBFILE_IID) + // { ===== begin nsIMdbFile methods ===== + + // { ----- begin pos methods ----- + NS_IMETHOD Tell(nsIMdbEnv* ev, mdb_pos* outPos) const = 0; + NS_IMETHOD Seek(nsIMdbEnv* ev, mdb_pos inPos, mdb_pos* outPos) = 0; + NS_IMETHOD Eof(nsIMdbEnv* ev, mdb_pos* outPos) = 0; + // } ----- end pos methods ----- + + // { ----- begin read methods ----- + NS_IMETHOD Read(nsIMdbEnv* ev, void* outBuf, mdb_size inSize, + mdb_size* outActualSize) = 0; + NS_IMETHOD Get(nsIMdbEnv* ev, void* outBuf, mdb_size inSize, mdb_pos inPos, + mdb_size* outActualSize) = 0; + // } ----- end read methods ----- + + // { ----- begin write methods ----- + NS_IMETHOD Write(nsIMdbEnv* ev, const void* inBuf, mdb_size inSize, + mdb_size* outActualSize) = 0; + NS_IMETHOD Put(nsIMdbEnv* ev, const void* inBuf, mdb_size inSize, + mdb_pos inPos, mdb_size* outActualSize) = 0; + NS_IMETHOD Flush(nsIMdbEnv* ev) = 0; + // } ----- end attribute methods ----- + + // { ----- begin path methods ----- + NS_IMETHOD Path(nsIMdbEnv* ev, mdbYarn* outFilePath) = 0; + // } ----- end path methods ----- + + // { ----- begin replacement methods ----- + NS_IMETHOD Steal(nsIMdbEnv* ev, nsIMdbFile* ioThief) = 0; + NS_IMETHOD Thief(nsIMdbEnv* ev, nsIMdbFile** acqThief) = 0; + // } ----- end replacement methods ----- + + // { ----- begin versioning methods ----- + NS_IMETHOD BecomeTrunk(nsIMdbEnv* ev) = 0; + // If this file is a file version branch created by calling AcquireBud(), + // BecomeTrunk() causes this file's content to replace the original + // file's content, typically by assuming the original file's identity. + // This default implementation of BecomeTrunk() does nothing, and this + // is appropriate behavior for files which are not branches, and is + // also the right behavior for files returned from AcquireBud() which are + // in fact the original file that has been truncated down to zero length. + + NS_IMETHOD AcquireBud(nsIMdbEnv* ev, nsIMdbHeap* ioHeap, + nsIMdbFile** acqBud) = + 0; // acquired file for new version of content + // AcquireBud() starts a new "branch" version of the file, empty of content, + // so that a new version of the file can be written. This new file + // can later be told to BecomeTrunk() the original file, so the branch + // created by budding the file will replace the original file. Some + // file subclasses might initially take the unsafe but expedient + // approach of simply truncating this file down to zero length, and + // then returning the same morkFile pointer as this, with an extra + // reference count increment. Note that the caller of AcquireBud() is + // expected to eventually call CutStrongRef() on the returned file + // in order to release the strong reference. High quality versions + // of morkFile subclasses will create entirely new files which later + // are renamed to become the old file, so that better transactional + // behavior is exhibited by the file, so crashes protect old files. + // Note that AcquireBud() is an illegal operation on readonly files. + // } ----- end versioning methods ----- + + // } ===== end nsIMdbFile methods ===== +}; + +NS_DEFINE_STATIC_IID_ACCESSOR(nsIMdbFile, NS_IMDBFILE_IID) + +/*| nsIMdbPort: a readonly interface to a specific database file. The mutable +**| nsIMdbStore interface is a subclass that includes writing behavior, but +**| most of the needed db methods appear in the readonly nsIMdbPort interface. +**| +**|| mdbYarn: note all nsIMdbPort and nsIMdbStore subclasses must guarantee null +**| termination of all strings written into mdbYarn instances, as long as +**| mYarn_Size and mYarn_Buf are nonzero. Even truncated string values must +**| be null terminated. This is more strict behavior than mdbYarn requires, +**| but it is part of the nsIMdbPort and nsIMdbStore interface. +**| +**|| attributes: methods are provided to distinguish a readonly port from a +**| mutable store, and whether a mutable store actually has any dirty content. +**| +**|| filepath: the file path used to open the port from the nsIMdbFactory can be +**| queried and discovered by GetPortFilePath(), which includes format info. +**| +**|| export: a port can write itself in other formats, with perhaps a typical +**| emphasis on text interchange formats used by other systems. A port can be +**| queried to determine its preferred export interchange format, and a port +**| can be queried to see whether a specific export format is supported. And +**| actually exporting a port requires a new destination file name and format. +**| +**|| tokens: a port supports queries about atomized strings to map tokens to +**| strings or strings to token integers. (All atomized strings must be in +**| US-ASCII iso-8859-1 Latin1 charset encoding.) When a port is actually a +**| mutable store and a string has not yet been atomized, then StringToToken() +**| will actually do so and modify the store. The QueryToken() method will not +**| atomize a string if it has not already been atomized yet, even in stores. +**| +**|| tables: other than string tokens, all port content is presented through +**| tables, which are ordered collections of rows. Tables are identified by +**| row scope and table kind, which might or might not be unique in a port, +**| depending on app convention. When tables are effectively unique, then +**| queries for specific scope and kind pairs will find those tables. To see +**| all tables that match specific row scope and table kind patterns, even in +**| the presence of duplicates, every port supports a GetPortTableCursor() +**| method that returns an iterator over all matching tables. Table kind is +**| considered scoped inside row scope, so passing a zero for table kind will +**| find all table kinds for some nonzero row scope. Passing a zero for row +**| scope will iterate over all tables in the port, in some undefined order. +**| (A new table can be added to a port using nsIMdbStore::NewTable(), even when +**| the requested scope and kind combination is already used by other tables.) +**| +**|| memory: callers can request that a database use less memory footprint in +**| several flavors, from an inconsequential idle flavor to a rather drastic +**| panic flavor. Callers might perform an idle purge very frequently if desired +**| with very little cost, since only normally scheduled memory management will +**| be conducted, such as freeing resources for objects scheduled to be dropped. +**| Callers should perform session memory purges infrequently because they might +**| involve costly scanning of data structures to removed cached content, and +**| session purges are recommended only when a caller experiences memory crunch. +**| Callers should only rarely perform a panic purge, in response to dire memory +**| straits, since this is likely to make db operations much more expensive +**| than they would be otherwise. A panic purge asks a database to free as much +**| memory as possible while staying effective and operational, because a caller +**| thinks application failure might otherwise occur. (Apps might better close +**| an open db, so panic purges only make sense when a db is urgently needed.) +|*/ +class nsIMdbPort : public nsISupports { + public: + // { ===== begin nsIMdbPort methods ===== + + // { ----- begin attribute methods ----- + NS_IMETHOD GetIsPortReadonly(nsIMdbEnv* ev, mdb_bool* outBool) = 0; + NS_IMETHOD GetIsStore(nsIMdbEnv* ev, mdb_bool* outBool) = 0; + NS_IMETHOD GetIsStoreAndDirty(nsIMdbEnv* ev, mdb_bool* outBool) = 0; + + NS_IMETHOD GetUsagePolicy(nsIMdbEnv* ev, mdbUsagePolicy* ioUsagePolicy) = 0; + + NS_IMETHOD SetUsagePolicy(nsIMdbEnv* ev, + const mdbUsagePolicy* inUsagePolicy) = 0; + // } ----- end attribute methods ----- + + // { ----- begin memory policy methods ----- + NS_IMETHOD IdleMemoryPurge( // do memory management already scheduled + nsIMdbEnv* ev, // context + mdb_size* outEstimatedBytesFreed) = + 0; // approximate bytes actually freed + + NS_IMETHOD SessionMemoryPurge( // request specific footprint decrease + nsIMdbEnv* ev, // context + mdb_size inDesiredBytesFreed, // approximate number of bytes wanted + mdb_size* outEstimatedBytesFreed) = + 0; // approximate bytes actually freed + + NS_IMETHOD PanicMemoryPurge( // desperately free all possible memory + nsIMdbEnv* ev, // context + mdb_size* outEstimatedBytesFreed) = + 0; // approximate bytes actually freed + // } ----- end memory policy methods ----- + + // { ----- begin filepath methods ----- + NS_IMETHOD GetPortFilePath( + nsIMdbEnv* ev, // context + mdbYarn* outFilePath, // name of file holding port content + mdbYarn* outFormatVersion) = 0; // file format description + + NS_IMETHOD GetPortFile(nsIMdbEnv* ev, // context + nsIMdbFile** acqFile) = + 0; // acquire file used by port or store + // } ----- end filepath methods ----- + + // { ----- begin export methods ----- + NS_IMETHOD BestExportFormat( // determine preferred export format + nsIMdbEnv* ev, // context + mdbYarn* outFormatVersion) = 0; // file format description + + // some tentative suggested import/export formats + // "ns:msg:db:port:format:ldif:ns4.0:passthrough" // necessary + // "ns:msg:db:port:format:ldif:ns4.5:utf8" // necessary + // "ns:msg:db:port:format:ldif:ns4.5:tabbed" + // "ns:msg:db:port:format:ldif:ns4.5:binary" // necessary + // "ns:msg:db:port:format:html:ns3.0:addressbook" // necessary + // "ns:msg:db:port:format:html:display:verbose" + // "ns:msg:db:port:format:html:display:concise" + // "ns:msg:db:port:format:mork:zany:verbose" // necessary + // "ns:msg:db:port:format:mork:zany:atomized" // necessary + // "ns:msg:db:port:format:rdf:xml" + // "ns:msg:db:port:format:xml:mork" + // "ns:msg:db:port:format:xml:display:verbose" + // "ns:msg:db:port:format:xml:display:concise" + // "ns:msg:db:port:format:xml:print:verbose" // recommended + // "ns:msg:db:port:format:xml:print:concise" + + NS_IMETHOD + CanExportToFormat( // can export content in given specific format? + nsIMdbEnv* ev, // context + const char* inFormatVersion, // file format description + mdb_bool* outCanExport) = 0; // whether ExportSource() might succeed + + NS_IMETHOD ExportToFormat( // export content in given specific format + nsIMdbEnv* ev, // context + // const char* inFilePath, // the file to receive exported content + nsIMdbFile* ioFile, // destination abstract file interface + const char* inFormatVersion, // file format description + nsIMdbThumb** acqThumb) = 0; // acquire thumb for incremental export + // Call nsIMdbThumb::DoMore() until done, or until the thumb is broken, and + // then the export will be finished. + + // } ----- end export methods ----- + + // { ----- begin token methods ----- + NS_IMETHOD TokenToString( // return a string name for an integer token + nsIMdbEnv* ev, // context + mdb_token inToken, // token for inTokenName inside this port + mdbYarn* outTokenName) = 0; // the type of table to access + + NS_IMETHOD StringToToken( // return an integer token for scope name + nsIMdbEnv* ev, // context + const char* inTokenName, // Latin1 string to tokenize if possible + mdb_token* outToken) = 0; // token for inTokenName inside this port + + // String token zero is never used and never supported. If the port + // is a mutable store, then StringToToken() to create a new + // association of inTokenName with a new integer token if possible. + // But a readonly port will return zero for an unknown scope name. + + NS_IMETHOD QueryToken( // like StringToToken(), but without adding + nsIMdbEnv* ev, // context + const char* inTokenName, // Latin1 string to tokenize if possible + mdb_token* outToken) = 0; // token for inTokenName inside this port + + // QueryToken() will return a string token if one already exists, + // but unlike StringToToken(), will not assign a new token if not + // already in use. + + // } ----- end token methods ----- + + // { ----- begin row methods ----- + NS_IMETHOD HasRow( // contains a row with the specified oid? + nsIMdbEnv* ev, // context + const mdbOid* inOid, // hypothetical row oid + mdb_bool* outHasRow) = 0; // whether GetRow() might succeed + + NS_IMETHOD GetRowRefCount( // get number of tables that contain a row + nsIMdbEnv* ev, // context + const mdbOid* inOid, // hypothetical row oid + mdb_count* outRefCount) = 0; // number of tables containing inRowKey + + NS_IMETHOD GetRow( // access one row with specific oid + nsIMdbEnv* ev, // context + const mdbOid* inOid, // hypothetical row oid + nsIMdbRow** acqRow) = 0; // acquire specific row (or null) + + // NS_IMETHOD + // GetPortRowCursor( // get cursor for all rows in specific scope + // nsIMdbEnv* ev, // context + // mdb_scope inRowScope, // row scope for row ids + // nsIMdbPortRowCursor** acqCursor) = 0; // all such rows in the port + + NS_IMETHOD FindRow( + nsIMdbEnv* ev, // search for row with matching cell + mdb_scope inRowScope, // row scope for row ids + mdb_column inColumn, // the column to search (and maintain an index) + const mdbYarn* inTargetCellValue, // cell value for which to search + mdbOid* outRowOid, // out row oid on match (or {0,-1} for no match) + nsIMdbRow** acqRow) = 0; // acquire matching row (or nil for no match) + // can be null if you only want the oid + // FindRow() searches for one row that has a cell in column inColumn with + // a contained value with the same form (i.e. charset) and is byte-wise + // identical to the blob described by yarn inTargetCellValue. Both content + // and form of the yarn must be an exact match to find a matching row. + // + // (In other words, both a yarn's blob bytes and form are significant. The + // form is not expected to vary in columns used for identity anyway. This + // is intended to make the cost of FindRow() cheaper for MDB implementors, + // since any cell value atomization performed internally must necessarily + // make yarn form significant in order to avoid data loss in atomization.) + // + // FindRow() can lazily create an index on attribute inColumn for all rows + // with that attribute in row space scope inRowScope, so that subsequent + // calls to FindRow() will perform faster. Such an index might or might + // not be persistent (but this seems desirable if it is cheap to do so). + // Note that lazy index creation in readonly DBs is not very feasible. + // + // This FindRow() interface assumes that attribute inColumn is effectively + // an alternative means of unique identification for a row in a rowspace, + // so correct behavior is only guaranteed when no duplicates for this col + // appear in the given set of rows. (If more than one row has the same cell + // value in this column, no more than one will be found; and cutting one of + // two duplicate rows can cause the index to assume no other such row lives + // in the row space, so future calls return nil for negative search results + // even though some duplicate row might still live within the rowspace.) + // + // In other words, the FindRow() implementation is allowed to assume simple + // hash tables mapping unique column keys to associated row values will be + // sufficient, where any duplication is not recorded because only one copy + // of a given key need be remembered. Implementors are not required to sort + // all rows by the specified column. + // } ----- end row methods ----- + + // { ----- begin table methods ----- + NS_IMETHOD HasTable( // supports a table with the specified oid? + nsIMdbEnv* ev, // context + const mdbOid* inOid, // hypothetical table oid + mdb_bool* outHasTable) = 0; // whether GetTable() might succeed + + NS_IMETHOD GetTable( // access one table with specific oid + nsIMdbEnv* ev, // context + const mdbOid* inOid, // hypothetical table oid + nsIMdbTable** acqTable) = 0; // acquire specific table (or null) + + NS_IMETHOD HasTableKind( // supports a table of the specified type? + nsIMdbEnv* ev, // context + mdb_scope inRowScope, // rid scope for row ids + mdb_kind inTableKind, // the type of table to access + mdb_count* outTableCount, // current number of such tables + mdb_bool* outSupportsTable) = 0; // whether GetTableKind() might succeed + + // row scopes to be supported include the following suggestions: + // "ns:msg:db:row:scope:address:cards:all" + // "ns:msg:db:row:scope:mail:messages:all" + // "ns:msg:db:row:scope:news:articles:all" + + // table kinds to be supported include the following suggestions: + // "ns:msg:db:table:kind:address:cards:main" + // "ns:msg:db:table:kind:address:lists:all" + // "ns:msg:db:table:kind:address:list" + // "ns:msg:db:table:kind:news:threads:all" + // "ns:msg:db:table:kind:news:thread" + // "ns:msg:db:table:kind:mail:threads:all" + // "ns:msg:db:table:kind:mail:thread" + + NS_IMETHOD GetTableKind( // access one (random) table of specific type + nsIMdbEnv* ev, // context + mdb_scope inRowScope, // row scope for row ids + mdb_kind inTableKind, // the type of table to access + mdb_count* outTableCount, // current number of such tables + mdb_bool* outMustBeUnique, // whether port can hold only one of these + nsIMdbTable** acqTable) = 0; // acquire scoped collection of rows + + NS_IMETHOD + GetPortTableCursor( // get cursor for all tables of specific type + nsIMdbEnv* ev, // context + mdb_scope inRowScope, // row scope for row ids + mdb_kind inTableKind, // the type of table to access + nsIMdbPortTableCursor** acqCursor) = 0; // all such tables in the port + // } ----- end table methods ----- + + // { ----- begin commit methods ----- + + NS_IMETHOD ShouldCompress( // store wastes at least inPercentWaste? + nsIMdbEnv* ev, // context + mdb_percent inPercentWaste, // 0..100 percent file size waste threshold + mdb_percent* outActualWaste, // 0..100 percent of file actually wasted + mdb_bool* outShould) = 0; // true when about inPercentWaste% is wasted + // ShouldCompress() returns true if the store can determine that the file + // will shrink by an estimated percentage of inPercentWaste% (or more) if + // CompressCommit() is called, because that percentage of the file seems + // to be recoverable free space. The granularity is only in terms of + // percentage points, and any value over 100 is considered equal to 100. + // + // If a store only has an approximate idea how much space might be saved + // during a compress, then a best guess should be made. For example, the + // Mork implementation might keep track of how much file space began with + // text content before the first updating transaction, and then consider + // all content following the start of the first transaction as potentially + // wasted space if it is all updates and not just new content. (This is + // a safe assumption in the sense that behavior will stabilize on a low + // estimate of wastage after a commit removes all transaction updates.) + // + // Some db formats might attempt to keep a very accurate reckoning of free + // space size, so a very accurate determination can be made. But other db + // formats might have difficulty determining size of free space, and might + // require some lengthy calculation to answer. This is the reason for + // passing in the percentage threshold of interest, so that such lengthy + // computations can terminate early as soon as at least inPercentWaste is + // found, so that the entire file need not be groveled when unnecessary. + // However, we hope implementations will always favor fast but imprecise + // heuristic answers instead of extremely slow but very precise answers. + // + // If the outActualWaste parameter is non-nil, it will be used to return + // the actual estimated space wasted as a percentage of file size. (This + // parameter is provided so callers need not call repeatedly with altered + // inPercentWaste values to isolate the actual wastage figure.) Note the + // actual wastage figure returned can exactly equal inPercentWaste even + // when this grossly underestimates the real figure involved, if the db + // finds it very expensive to determine the extent of wastage after it is + // known to at least exceed inPercentWaste. Note we expect that whenever + // outShould returns true, that outActualWaste returns >= inPercentWaste. + // + // The effect of different inPercentWaste values is not very uniform over + // the permitted range. For example, 50 represents 50% wastage, or a file + // that is about double what it should be ideally. But 99 represents 99% + // wastage, or a file that is about ninety-nine times as big as it should + // be ideally. In the smaller direction, 25 represents 25% wastage, or + // a file that is only 33% larger than it should be ideally. + // + // Callers can determine what policy they want to use for considering when + // a file holds too much wasted space, and express this as a percentage + // of total file size to pass as in the inPercentWaste parameter. A zero + // likely returns always trivially true, and 100 always trivially false. + // The great majority of callers are expected to use values from 25 to 75, + // since most plausible thresholds for compressing might fall between the + // extremes of 133% of ideal size and 400% of ideal size. (Presumably the + // larger a file gets, the more important the percentage waste involved, so + // a sliding scale for compress thresholds might use smaller numbers for + // much bigger file sizes.) + + // } ----- end commit methods ----- + + // } ===== end nsIMdbPort methods ===== +}; + +/*| nsIMdbStore: a mutable interface to a specific database file. +**| +**|| tables: one can force a new table to exist in a store with NewTable() +**| and nonzero values for both row scope and table kind. (If one wishes only +**| one table of a certain kind, then one might look for it first using the +**| GetTableKind() method). One can pass inMustBeUnique to force future +**| users of this store to be unable to create other tables with the same pair +**| of scope and kind attributes. When inMustBeUnique is true, and the table +**| with the given scope and kind pair already exists, then the existing one +**| is returned instead of making a new table. Similarly, if one passes false +**| for inMustBeUnique, but the table kind has already been marked unique by a +**| previous user of the store, then the existing unique table is returned. +**| +**|| import: all or some of another port's content can be imported by calling +**| AddPortContent() with a row scope identifying the extent of content to +**| be imported. A zero row scope will import everything. A nonzero row +**| scope will only import tables with a matching row scope. Note that one +**| must somehow find a way to negotiate possible conflicts between existing +**| row content and imported row content, and this involves a specific kind of +**| definition for row identity involving either row IDs or unique attributes, +**| or some combination of these two. At the moment I am just going to wave +**| my hands, and say the default behavior is to assign all new row identities +**| to all imported content, which will result in no merging of content; this +**| must change later because it is unacceptable in some contexts. +**| +**|| commits: to manage modifications in a mutable store, very few methods are +**| really needed to indicate global policy choices that are independent of +**| the actual modifications that happen in objects at the level of tables, +**| rows, and cells, etc. The most important policy to specify is which sets +**| of changes are considered associated in a manner such that they should be +**| applied together atomically to a given store. We call each such group of +**| changes a transaction. We handle three different grades of transaction, +**| but they differ only in semantic significance to the application, and are +**| not intended to nest. (If small transactions were nested inside large +**| transactions, that would imply that a single large transaction must be +**| atomic over all the contained small transactions; but actually we intend +**| smalls transaction never be undone once committed due to, say, aborting a +**| transaction of greater significance.) The small, large, and session level +**| commits have equal granularity, and differ only in risk of loss from the +**| perspective of an application. Small commits characterize changes that +**| can be lost with relatively small risk, so small transactions can delay +**| until later if they are expensive or impractical to commit. Large commits +**| involve changes that would probably inconvenience users if lost, so the +**| need to pay costs of writing is rather greater than with small commits. +**| Session commits are last ditch attempts to save outstanding changes before +**| stopping the use of a particular database, so there will be no later point +**| in time to save changes that have been delayed due to possible high cost. +**| If large commits are never delayed, then a session commit has about the +**| same performance effect as another large commit; but if small and large +**| commits are always delayed, then a session commit is likely to be rather +**| expensive as a runtime cost compared to any earlier database usage. +**| +**|| aborts: the only way to abort changes to a store is by closing the store. +**| So there is no specific method for causing any abort. Stores must discard +**| all changes made that are uncommitted when a store is closed. This design +**| choice makes the implementations of tables, rows, and cells much less +**| complex because they need not maintain a record of undobable changes. When +**| a store is closed, presumably this precipitates the closure of all tables, +**| rows, and cells in the store as well. So an application can revert the +**| state of a store in the user interface by quietly closing and reopening a +**| store, because this will discard uncommitted changes and show old content. +**| This implies an app that closes a store will need to send a "scramble" +**| event notification to any views that depend on old discarded content. +|*/ + +#define NS_IMDBSTORE_IID_STR "74d6218d-44b0-43b5-9ebe-69a17dfb562c" +#define NS_IMDBSTORE_IID \ + { \ + 0x74d6218d, 0x44b0, 0x43b5, { \ + 0x9e, 0xbe, 0x69, 0xa1, 0x7d, 0xfb, 0x56, 0x2c \ + } \ + } + +class nsIMdbStore : public nsIMdbPort { + public: + NS_DECLARE_STATIC_IID_ACCESSOR(NS_IMDBSTORE_IID) + + // { ===== begin nsIMdbStore methods ===== + + // { ----- begin table methods ----- + NS_IMETHOD NewTable( // make one new table of specific type + nsIMdbEnv* ev, // context + mdb_scope inRowScope, // row scope for row ids + mdb_kind inTableKind, // the type of table to access + mdb_bool inMustBeUnique, // whether store can hold only one of these + const mdbOid* inOptionalMetaRowOid, // can be nil to avoid specifying + nsIMdbTable** acqTable) = 0; // acquire scoped collection of rows + + NS_IMETHOD NewTableWithOid( // make one new table of specific type + nsIMdbEnv* ev, // context + const mdbOid* inOid, // caller assigned oid + mdb_kind inTableKind, // the type of table to access + mdb_bool inMustBeUnique, // whether store can hold only one of these + const mdbOid* inOptionalMetaRowOid, // can be nil to avoid specifying + nsIMdbTable** acqTable) = 0; // acquire scoped collection of rows + // } ----- end table methods ----- + + // { ----- begin row scope methods ----- + NS_IMETHOD RowScopeHasAssignedIds( + nsIMdbEnv* ev, + mdb_scope inRowScope, // row scope for row ids + mdb_bool* outCallerAssigned, // nonzero if caller assigned specified + mdb_bool* outStoreAssigned) = + 0; // nonzero if store db assigned specified + + NS_IMETHOD SetCallerAssignedIds( + nsIMdbEnv* ev, + mdb_scope inRowScope, // row scope for row ids + mdb_bool* outCallerAssigned, // nonzero if caller assigned specified + mdb_bool* outStoreAssigned) = + 0; // nonzero if store db assigned specified + + NS_IMETHOD SetStoreAssignedIds( + nsIMdbEnv* ev, + mdb_scope inRowScope, // row scope for row ids + mdb_bool* outCallerAssigned, // nonzero if caller assigned specified + mdb_bool* outStoreAssigned) = + 0; // nonzero if store db assigned specified + // } ----- end row scope methods ----- + + // { ----- begin row methods ----- + NS_IMETHOD NewRowWithOid(nsIMdbEnv* ev, // new row w/ caller assigned oid + const mdbOid* inOid, // caller assigned oid + nsIMdbRow** acqRow) = 0; // create new row + + NS_IMETHOD NewRow(nsIMdbEnv* ev, // new row with db assigned oid + mdb_scope inRowScope, // row scope for row ids + nsIMdbRow** acqRow) = 0; // create new row + // Note this row must be added to some table or cell child before the + // store is closed in order to make this row persist across sessions. + + // } ----- end row methods ----- + + // { ----- begin import/export methods ----- + NS_IMETHOD ImportContent( // import content from port + nsIMdbEnv* ev, // context + mdb_scope inRowScope, // scope for rows (or zero for all?) + nsIMdbPort* ioPort, // the port with content to add to store + nsIMdbThumb** acqThumb) = 0; // acquire thumb for incremental import + // Call nsIMdbThumb::DoMore() until done, or until the thumb is broken, and + // then the import will be finished. + + NS_IMETHOD ImportFile( // import content from port + nsIMdbEnv* ev, // context + nsIMdbFile* ioFile, // the file with content to add to store + nsIMdbThumb** acqThumb) = 0; // acquire thumb for incremental import + // Call nsIMdbThumb::DoMore() until done, or until the thumb is broken, and + // then the import will be finished. + // } ----- end import/export methods ----- + + // { ----- begin hinting methods ----- + NS_IMETHOD + ShareAtomColumnsHint( // advise re shared column content atomizing + nsIMdbEnv* ev, // context + mdb_scope inScopeHint, // zero, or suggested shared namespace + const mdbColumnSet* inColumnSet) = 0; // cols desired tokenized together + + NS_IMETHOD + AvoidAtomColumnsHint( // advise column with poor atomizing prospects + nsIMdbEnv* ev, // context + const mdbColumnSet* inColumnSet) = + 0; // cols with poor atomizing prospects + // } ----- end hinting methods ----- + + // { ----- begin commit methods ----- + NS_IMETHOD LargeCommit( // save important changes if at all possible + nsIMdbEnv* ev, // context + nsIMdbThumb** acqThumb) = 0; // acquire thumb for incremental commit + // Call nsIMdbThumb::DoMore() until done, or until the thumb is broken, and + // then the commit will be finished. Note the store is effectively write + // locked until commit is finished or canceled through the thumb instance. + // Until the commit is done, the store will report it has readonly status. + + NS_IMETHOD SessionCommit( // save all changes if large commits delayed + nsIMdbEnv* ev, // context + nsIMdbThumb** acqThumb) = 0; // acquire thumb for incremental commit + // Call nsIMdbThumb::DoMore() until done, or until the thumb is broken, and + // then the commit will be finished. Note the store is effectively write + // locked until commit is finished or canceled through the thumb instance. + // Until the commit is done, the store will report it has readonly status. + + NS_IMETHOD + CompressCommit( // commit and make db physically smaller if possible + nsIMdbEnv* ev, // context + nsIMdbThumb** acqThumb) = 0; // acquire thumb for incremental commit + // Call nsIMdbThumb::DoMore() until done, or until the thumb is broken, and + // then the commit will be finished. Note the store is effectively write + // locked until commit is finished or canceled through the thumb instance. + // Until the commit is done, the store will report it has readonly status. + + // } ----- end commit methods ----- + + // } ===== end nsIMdbStore methods ===== +}; + +NS_DEFINE_STATIC_IID_ACCESSOR(nsIMdbStore, NS_IMDBSTORE_IID) + +/*| nsIMdbCursor: base cursor class for iterating row cells and table rows +**| +**|| count: the number of elements in the collection (table or row) +**| +**|| seed: the change count in the underlying collection, which is synced +**| with the collection when the iteration position is set, and henceforth +**| acts to show whether the iter has lost collection synchronization, in +**| case it matters to clients whether any change happens during iteration. +**| +**|| pos: the position of the current element in the collection. Negative +**| means a position logically before the first element. A positive value +**| equal to count (or larger) implies a position after the last element. +**| To iterate over all elements, set the position to negative, so subsequent +**| calls to any 'next' method will access the first collection element. +**| +**|| doFailOnSeedOutOfSync: whether a cursor should return an error if the +**| cursor's snapshot of a table's seed becomes stale with respect the table's +**| current seed value (which implies the iteration is less than total) in +**| between to cursor calls that actually access collection content. By +**| default, a cursor should assume this attribute is false until specified, +**| so that iterations quietly try to re-sync when they lose coherence. +|*/ + +#define NS_IMDBCURSOR_IID_STR "a0c37337-6ebc-474c-90db-e65ea0b850aa" + +#define NS_IMDBCURSOR_IID \ + { \ + 0xa0c37337, 0x6ebc, 0x474c, { \ + 0x90, 0xdb, 0xe6, 0x5e, 0xa0, 0xb8, 0x50, 0xaa \ + } \ + } + +class nsIMdbCursor : public nsISupports { // collection iterator + public: + NS_DECLARE_STATIC_IID_ACCESSOR(NS_IMDBCURSOR_IID) + // { ===== begin nsIMdbCursor methods ===== + + // { ----- begin attribute methods ----- + NS_IMETHOD GetCount(nsIMdbEnv* ev, mdb_count* outCount) = 0; // readonly + NS_IMETHOD GetSeed(nsIMdbEnv* ev, mdb_seed* outSeed) = 0; // readonly + + NS_IMETHOD SetPos(nsIMdbEnv* ev, mdb_pos inPos) = 0; // mutable + NS_IMETHOD GetPos(nsIMdbEnv* ev, mdb_pos* outPos) = 0; + + NS_IMETHOD SetDoFailOnSeedOutOfSync(nsIMdbEnv* ev, mdb_bool inFail) = 0; + NS_IMETHOD GetDoFailOnSeedOutOfSync(nsIMdbEnv* ev, mdb_bool* outFail) = 0; + // } ----- end attribute methods ----- + + // } ===== end nsIMdbCursor methods ===== +}; + +NS_DEFINE_STATIC_IID_ACCESSOR(nsIMdbCursor, NS_IMDBCURSOR_IID) + +#define NS_IMDBPORTTABLECURSOR_IID_STR = "f181a41e-933d-49b3-af93-20d3634b8b78" + +#define NS_IMDBPORTTABLECURSOR_IID \ + { \ + 0xf181a41e, 0x933d, 0x49b3, { \ + 0xaf, 0x93, 0x20, 0xd3, 0x63, 0x4b, 0x8b, 0x78 \ + } \ + } + +/*| nsIMdbPortTableCursor: cursor class for iterating port tables +**| +**|| port: the cursor is associated with a specific port, which can be +**| set to a different port (which resets the position to -1 so the +**| next table acquired is the first in the port. +**| +|*/ +class nsIMdbPortTableCursor : public nsISupports { // table collection iterator + public: + NS_DECLARE_STATIC_IID_ACCESSOR(NS_IMDBPORTTABLECURSOR_IID) + // { ===== begin nsIMdbPortTableCursor methods ===== + + // { ----- begin attribute methods ----- + NS_IMETHOD SetPort(nsIMdbEnv* ev, nsIMdbPort* ioPort) = 0; // sets pos to -1 + NS_IMETHOD GetPort(nsIMdbEnv* ev, nsIMdbPort** acqPort) = 0; + + NS_IMETHOD SetRowScope(nsIMdbEnv* ev, // sets pos to -1 + mdb_scope inRowScope) = 0; + NS_IMETHOD GetRowScope(nsIMdbEnv* ev, mdb_scope* outRowScope) = 0; + // setting row scope to zero iterates over all row scopes in port + + NS_IMETHOD SetTableKind(nsIMdbEnv* ev, // sets pos to -1 + mdb_kind inTableKind) = 0; + NS_IMETHOD GetTableKind(nsIMdbEnv* ev, mdb_kind* outTableKind) = 0; + // setting table kind to zero iterates over all table kinds in row scope + // } ----- end attribute methods ----- + + // { ----- begin table iteration methods ----- + NS_IMETHOD NextTable( // get table at next position in the db + nsIMdbEnv* ev, // context + nsIMdbTable** acqTable) = 0; // the next table in the iteration + // } ----- end table iteration methods ----- + + // } ===== end nsIMdbPortTableCursor methods ===== +}; + +NS_DEFINE_STATIC_IID_ACCESSOR(nsIMdbPortTableCursor, NS_IMDBPORTTABLECURSOR_IID) + +/*| nsIMdbCollection: an object that collects a set of other objects as members. +**| The main purpose of this base class is to unify the perceived semantics +**| of tables and rows where their collection behavior is similar. This helps +**| isolate the mechanics of collection behavior from the other semantics that +**| are more characteristic of rows and tables. +**| +**|| count: the number of objects in a collection is the member count. (Some +**| collection interfaces call this attribute the 'size', but that can be a +**| little ambiguous, and counting actual members is harder to confuse.) +**| +**|| seed: the seed of a collection is a counter for changes in membership in +**| a specific collection. This seed should change when members are added to +**| or removed from a collection, but not when a member changes internal state. +**| The seed should also change whenever the internal collection of members has +**| a complex state change that reorders member positions (say by sorting) that +**| would affect the nature of an iteration over that collection of members. +**| The purpose of a seed is to inform any outstanding collection cursors that +**| they might be stale, without incurring the cost of broadcasting an event +**| notification to such cursors, which would need more data structure support. +**| Presumably a cursor in a particular mdb code suite has much more direct +**| access to a collection seed member slot that this abstract COM interface, +**| so this information is intended more for clients outside mdb that want to +**| make inferences similar to those made by the collection cursors. The seed +**| value as an integer magnitude is not very important, and callers should not +**| assume meaningful information can be derived from an integer value beyond +**| whether it is equal or different from a previous inspection. A seed uses +**| integers of many bits in order to make the odds of wrapping and becoming +**| equal to an earlier seed value have probability that is vanishingly small. +**| +**|| port: every collection is associated with a specific database instance. +**| +**|| cursor: a subclass of nsIMdbCursor suitable for this specific collection +**| subclass. The ability to GetCursor() from the base nsIMdbCollection class +**| is not really as useful as getting a more specifically typed cursor more +**| directly from the base class without any casting involved. So including +**| this method here is more for conceptual illustration. +**| +**|| oid: every collection has an identity that persists from session to +**| session. Implementations are probably able to distinguish row IDs from +**| table IDs, but we don't specify anything official in this regard. A +**| collection has the same identity for the lifetime of the collection, +**| unless identity is swapped with another collection by means of a call to +**| BecomeContent(), which is considered a way to swap a new representation +**| for an old well-known object. (Even so, only content appears to change, +**| while the identity seems to stay the same.) +**| +**|| become: developers can effectively cause two objects to swap identities, +**| in order to effect a complete swap between what persistent content is +**| represented by two oids. The caller should consider this a content swap, +**| and not identity wap, because identities will seem to stay the same while +**| only content changes. However, implementations will likely do this +**| internally by swapping identities. Callers must swap content only +**| between objects of similar type, such as a row with another row, and a +**| table with another table, because implementations need not support +**| cross-object swapping because it might break object name spaces. +**| +**|| dropping: when a caller expects a row or table will no longer be used, the +**| caller can tell the collection to 'drop activity', which means the runtime +**| object can have its internal representation purged to save memory or any +**| other resource that is being consumed by the collection's representation. +**| This has no effect on the collection's persistent content or semantics, +**| and is only considered a runtime effect. After a collection drops +**| activity, the object should still be as usable as before (because it has +**| NOT been closed), but further usage can be expensive to re-instate because +**| it might involve reallocating space and/or re-reading disk space. But +**| since this future usage is not expected, the caller does not expect to +**| pay the extra expense. An implementation can choose to implement +**| 'dropping activity' in different ways, or even not at all if this +**| operation is not really feasible. Callers cannot ask objects whether they +**| are 'dropped' or not, so this should be transparent. (Note that +**| implementors might fear callers do not really know whether future +**| usage will occur, and therefore might delay the act of dropping until +**| the near future, until seeing whether the object is used again +**| immediately elsewhere. Such use soon after the drop request might cause +**| the drop to be cancelled.) +|*/ +class nsIMdbCollection : public nsISupports { // sequence of objects + public: + // { ===== begin nsIMdbCollection methods ===== + + // { ----- begin attribute methods ----- + NS_IMETHOD GetSeed(nsIMdbEnv* ev, + mdb_seed* outSeed) = 0; // member change count + NS_IMETHOD GetCount(nsIMdbEnv* ev, + mdb_count* outCount) = 0; // member count + + NS_IMETHOD GetPort(nsIMdbEnv* ev, + nsIMdbPort** acqPort) = 0; // collection container + // } ----- end attribute methods ----- + + // { ----- begin cursor methods ----- + NS_IMETHOD GetCursor( // make a cursor starting iter at inMemberPos + nsIMdbEnv* ev, // context + mdb_pos inMemberPos, // zero-based ordinal pos of member in collection + nsIMdbCursor** acqCursor) = 0; // acquire new cursor instance + // } ----- end cursor methods ----- + + // { ----- begin ID methods ----- + NS_IMETHOD GetOid(nsIMdbEnv* ev, + mdbOid* outOid) = 0; // read object identity + NS_IMETHOD BecomeContent(nsIMdbEnv* ev, + const mdbOid* inOid) = 0; // exchange content + // } ----- end ID methods ----- + + // { ----- begin activity dropping methods ----- + NS_IMETHOD DropActivity( // tell collection usage no longer expected + nsIMdbEnv* ev) = 0; + // } ----- end activity dropping methods ----- + + // } ===== end nsIMdbCollection methods ===== +}; + +/*| nsIMdbTable: an ordered collection of rows +**| +**|| row scope: an integer token for an atomized string in this database +**| that names a space for row IDs. This attribute of a table is intended +**| as guidance metainformation that helps with searching a database for +**| tables that operate on collections of rows of the specific type. By +**| convention, a table with a specific row scope is expected to focus on +**| containing rows that belong to that scope, however exceptions are easily +**| allowed because all rows in a table are known by both row ID and scope. +**| (A table with zero row scope is never allowed because this would make it +**| ambiguous to use a zero row scope when iterating over tables in a port to +**| indicate that all row scopes should be seen by a cursor.) +**| +**|| table kind: an integer token for an atomized string in this database +**| that names a kind of table as a subset of the associated row scope. This +**| attribute is intended as guidance metainformation to clarify the role of +**| this table with respect to other tables in the same row scope, and this +**| also helps search for such tables in a database. By convention, a table +**| with a specific table kind has a consistent role for containing rows with +**| respect to other collections of such rows in the same row scope. Also by +**| convention, at least one table in a row scope has a table kind purporting +**| to contain ALL the rows that belong in that row scope, so that at least +**| one table exists that allows all rows in a scope to be iterated over. +**| (A table with zero table kind is never allowed because this would make it +**| ambiguous to use a zero table kind when iterating over tables in a port to +**| indicate that all table kinds in a row scope should be seen by a cursor.) +**| +**|| port: every table is considered part of some port that contains the +**| table, so that closing the containing port will cause the table to be +**| indirectly closed as well. We make it easy to get the containing port for +**| a table, because the port supports important semantic interfaces that will +**| affect how content in table is presented; the most important port context +**| that affects a table is specified by the set of token to string mappings +**| that affect all tokens used throughout the database, and which drive the +**| meanings of row scope, table kind, cell columns, etc. +**| +**|| cursor: a cursor that iterates over the rows in this table, where rows +**| have zero-based index positions from zero to count-1. Making a cursor +**| with negative position will next iterate over the first row in the table. +**| +**|| position: given any position from zero to count-1, a table will return +**| the row ID and row scope for the row at that position. (One can use the +**| GetRowAllCells() method to read that row, or else use a row cursor to both +**| get the row at some position and read its content at the same time.) The +**| position depends on whether a table is sorted, and upon the actual sort. +**| Note that moving a row's position is only possible in unsorted tables. +**| +**|| row set: every table contains a collection of rows, where a member row is +**| referenced by the table using the row ID and row scope for the row. No +**| single table owns a given row instance, because rows are effectively ref- +**| counted and destroyed only when the last table removes a reference to that +**| particular row. (But a row can be emptied of all content no matter how +**| many refs exist, and this might be the next best thing to destruction.) +**| Once a row exists in a least one table (after NewRow() is called), then it +**| can be added to any other table by calling AddRow(), or removed from any +**| table by calling CutRow(), or queried as a member by calling HasRow(). A +**| row can only be added to a table once, and further additions do nothing and +**| complain not at all. Cutting a row from a table only does something when +**| the row was actually a member, and otherwise does nothing silently. +**| +**|| row ref count: one can query the number of tables (and/or cells) +**| containing a row as a member or a child. +**| +**|| row content: one can access or modify the cell content in a table's row +**| by moving content to or from an instance of nsIMdbRow. Note that nsIMdbRow +**| never represents the actual row inside a table, and this is the reason +**| why nsIMdbRow instances do not have row IDs or row scopes. So an instance +**| of nsIMdbRow always and only contains a snapshot of some or all content in +**| past, present, or future persistent row inside a table. This means that +**| reading and writing rows in tables has strictly copy semantics, and we +**| currently do not plan any exceptions for specific performance reasons. +**| +**|| sorting: note all rows are assumed sorted by row ID as a secondary +**| sort following the primary column sort, when table rows are sorted. +**| +**|| indexes: +|*/ + +#define NS_IMDBTABLE_IID_STR = "fe11bc98-d02b-4128-9fac-87042fdf9639" + +#define NS_IMDBTABLE_IID \ + { \ + 0xfe11bc98, 0xd02b, 0x4128, { \ + 0x9f, 0xac, 0x87, 0x04, 0x2f, 0xdf, 0x96, 0x39 \ + } \ + } + +class nsIMdbTable : public nsIMdbCollection { // a collection of rows + public: + NS_DECLARE_STATIC_IID_ACCESSOR(NS_IMDBTABLE_IID) + // { ===== begin nsIMdbTable methods ===== + + // { ----- begin meta attribute methods ----- + NS_IMETHOD SetTablePriority(nsIMdbEnv* ev, mdb_priority inPrio) = 0; + NS_IMETHOD GetTablePriority(nsIMdbEnv* ev, mdb_priority* outPrio) = 0; + + NS_IMETHOD GetTableBeVerbose(nsIMdbEnv* ev, mdb_bool* outBeVerbose) = 0; + NS_IMETHOD SetTableBeVerbose(nsIMdbEnv* ev, mdb_bool inBeVerbose) = 0; + + NS_IMETHOD GetTableIsUnique(nsIMdbEnv* ev, mdb_bool* outIsUnique) = 0; + + NS_IMETHOD GetTableKind(nsIMdbEnv* ev, mdb_kind* outTableKind) = 0; + NS_IMETHOD GetRowScope(nsIMdbEnv* ev, mdb_scope* outRowScope) = 0; + + NS_IMETHOD GetMetaRow( + nsIMdbEnv* ev, // context + const mdbOid* inOptionalMetaRowOid, // can be nil to avoid specifying + mdbOid* outOid, // output meta row oid, can be nil to suppress output + nsIMdbRow** acqRow) = 0; // acquire table's unique singleton meta row + // The purpose of a meta row is to support the persistent recording of + // meta info about a table as cells put into the distinguished meta row. + // Each table has exactly one meta row, which is not considered a member + // of the collection of rows inside the table. The only way to tell + // whether a row is a meta row is by the fact that it is returned by this + // GetMetaRow() method from some table. Otherwise nothing distinguishes + // a meta row from any other row. A meta row can be used anyplace that + // any other row can be used, and can even be put into other tables (or + // the same table) as a table member, if this is useful for some reason. + // The first attempt to access a table's meta row using GetMetaRow() will + // cause the meta row to be created if it did not already exist. When the + // meta row is created, it will have the row oid that was previously + // requested for this table's meta row; or if no oid was ever explicitly + // specified for this meta row, then a unique oid will be generated in + // the row scope named "m" (so obviously MDB clients should not + // manually allocate any row IDs from that special meta scope namespace). + // The meta row oid can be specified either when the table is created, or + // else the first time that GetMetaRow() is called, by passing a non-nil + // pointer to an oid for parameter inOptionalMetaRowOid. The meta row's + // actual oid is returned in outOid (if this is a non-nil pointer), and + // it will be different from inOptionalMetaRowOid when the meta row was + // already given a different oid earlier. + // } ----- end meta attribute methods ----- + + // { ----- begin cursor methods ----- + NS_IMETHOD + GetTableRowCursor( // make a cursor, starting iteration at inRowPos + nsIMdbEnv* ev, // context + mdb_pos inRowPos, // zero-based ordinal position of row in table + nsIMdbTableRowCursor** acqCursor) = 0; // acquire new cursor instance + // } ----- end row position methods ----- + + // { ----- begin row position methods ----- + NS_IMETHOD PosToOid( // get row member for a table position + nsIMdbEnv* ev, // context + mdb_pos inRowPos, // zero-based ordinal position of row in table + mdbOid* outOid) = 0; // row oid at the specified position + + NS_IMETHOD OidToPos( // test for the table position of a row member + nsIMdbEnv* ev, // context + const mdbOid* inOid, // row to find in table + mdb_pos* outPos) = 0; // zero-based ordinal position of row in table + + NS_IMETHOD PosToRow( // test for the table position of a row member + nsIMdbEnv* ev, // context + mdb_pos inRowPos, // zero-based ordinal position of row in table + nsIMdbRow** acqRow) = 0; // acquire row at table position inRowPos + + NS_IMETHOD RowToPos( // test for the table position of a row member + nsIMdbEnv* ev, // context + nsIMdbRow* ioRow, // row to find in table + mdb_pos* outPos) = 0; // zero-based ordinal position of row in table + // } ----- end row position methods ----- + + // { ----- begin oid set methods ----- + NS_IMETHOD AddOid( // make sure the row with inOid is a table member + nsIMdbEnv* ev, // context + const mdbOid* inOid) = 0; // row to ensure membership in table + + NS_IMETHOD HasOid( // test for the table position of a row member + nsIMdbEnv* ev, // context + const mdbOid* inOid, // row to find in table + mdb_bool* outHasOid) = 0; // whether inOid is a member row + + NS_IMETHOD CutOid( // make sure the row with inOid is not a member + nsIMdbEnv* ev, // context + const mdbOid* inOid) = 0; // row to remove from table + // } ----- end oid set methods ----- + + // { ----- begin row set methods ----- + NS_IMETHOD NewRow( // create a new row instance in table + nsIMdbEnv* ev, // context + mdbOid* + ioOid, // please use minus one (unbound) rowId for db-assigned IDs + nsIMdbRow** acqRow) = 0; // create new row + + NS_IMETHOD AddRow( // make sure the row with inOid is a table member + nsIMdbEnv* ev, // context + nsIMdbRow* ioRow) = 0; // row to ensure membership in table + + NS_IMETHOD HasRow( // test for the table position of a row member + nsIMdbEnv* ev, // context + nsIMdbRow* ioRow, // row to find in table + mdb_bool* outHasRow) = 0; // whether row is a table member + + NS_IMETHOD CutRow( // make sure the row with inOid is not a member + nsIMdbEnv* ev, // context + nsIMdbRow* ioRow) = 0; // row to remove from table + + NS_IMETHOD CutAllRows( // remove all rows from the table + nsIMdbEnv* ev) = 0; // context + // } ----- end row set methods ----- + + // { ----- begin hinting methods ----- + NS_IMETHOD SearchColumnsHint( // advise re future expected search cols + nsIMdbEnv* ev, // context + const mdbColumnSet* inColumnSet) = 0; // columns likely to be searched + + NS_IMETHOD SortColumnsHint( // advise re future expected sort columns + nsIMdbEnv* ev, // context + const mdbColumnSet* inColumnSet) = 0; // columns for likely sort requests + + NS_IMETHOD StartBatchChangeHint( // advise before many adds and cuts + nsIMdbEnv* ev, // context + const void* inLabel) = 0; // intend unique address to match end call + // If batch starts nest by virtue of nesting calls in the stack, then + // the address of a local variable makes a good batch start label that + // can be used at batch end time, and such addresses remain unique. + + NS_IMETHOD EndBatchChangeHint( // advise before many adds and cuts + nsIMdbEnv* ev, // context + const void* inLabel) = 0; // label matching start label + // Suppose a table is maintaining one or many sort orders for a table, + // so that every row added to the table must be inserted in each sort, + // and every row cut must be removed from each sort. If a db client + // intends to make many such changes before needing any information + // about the order or positions of rows inside a table, then a client + // might tell the table to start batch changes in order to disable + // sorting of rows for the interim. Presumably a table will then do + // a full sort of all rows at need when the batch changes end, or when + // a surprise request occurs for row position during batch changes. + // } ----- end hinting methods ----- + + // { ----- begin searching methods ----- + NS_IMETHOD FindRowMatches( // search variable number of sorted cols + nsIMdbEnv* ev, // context + const mdbYarn* + inPrefix, // content to find as prefix in row's column cell + nsIMdbTableRowCursor** acqCursor) = 0; // set of matching rows + + NS_IMETHOD GetSearchColumns( // query columns used by FindRowMatches() + nsIMdbEnv* ev, // context + mdb_count* outCount, // context + mdbColumnSet* outColSet) = 0; // caller supplied space to put columns + // GetSearchColumns() returns the columns actually searched when the + // FindRowMatches() method is called. No more than mColumnSet_Count + // slots of mColumnSet_Columns will be written, since mColumnSet_Count + // indicates how many slots are present in the column array. The + // actual number of search column used by the table is returned in + // the outCount parameter; if this number exceeds mColumnSet_Count, + // then a caller needs a bigger array to read the entire column set. + // The minimum of mColumnSet_Count and outCount is the number slots + // in mColumnSet_Columns that were actually written by this method. + // + // Callers are expected to change this set of columns by calls to + // nsIMdbTable::SearchColumnsHint() or SetSearchSorting(), or both. + // } ----- end searching methods ----- + + // { ----- begin sorting methods ----- + // sorting: note all rows are assumed sorted by row ID as a secondary + // sort following the primary column sort, when table rows are sorted. + + NS_IMETHOD + CanSortColumn( // query which column is currently used for sorting + nsIMdbEnv* ev, // context + mdb_column inColumn, // column to query sorting potential + mdb_bool* outCanSort) = 0; // whether the column can be sorted + + NS_IMETHOD GetSorting( // view same table in particular sorting + nsIMdbEnv* ev, // context + mdb_column inColumn, // requested new column for sorting table + nsIMdbSorting** acqSorting) = 0; // acquire sorting for column + + NS_IMETHOD SetSearchSorting( // use this sorting in FindRowMatches() + nsIMdbEnv* ev, // context + mdb_column inColumn, // often same as nsIMdbSorting::GetSortColumn() + nsIMdbSorting* ioSorting) = 0; // requested sorting for some column + // SetSearchSorting() attempts to inform the table that ioSorting + // should be used during calls to FindRowMatches() for searching + // the column which is actually sorted by ioSorting. This method + // is most useful in conjunction with nsIMdbSorting::SetCompare(), + // because otherwise a caller would not be able to override the + // comparison ordering method used during searches. Note that some + // database implementations might be unable to use an arbitrarily + // specified sort order, either due to schema or runtime interface + // constraints, in which case ioSorting might not actually be used. + // Presumably ioSorting is an instance that was returned from some + // earlier call to nsIMdbTable::GetSorting(). A caller can also + // use nsIMdbTable::SearchColumnsHint() to specify desired change + // in which columns are sorted and searched by FindRowMatches(). + // + // A caller can pass a nil pointer for ioSorting to request that + // column inColumn no longer be used at all by FindRowMatches(). + // But when ioSorting is non-nil, then inColumn should match the + // column actually sorted by ioSorting; when these do not agree, + // implementations are instructed to give precedence to the column + // specified by ioSorting (so this means callers might just pass + // zero for inColumn when ioSorting is also provided, since then + // inColumn is both redundant and ignored). + // } ----- end sorting methods ----- + + // { ----- begin moving methods ----- + // moving a row does nothing unless a table is currently unsorted + + NS_IMETHOD MoveOid( // change position of row in unsorted table + nsIMdbEnv* ev, // context + const mdbOid* inOid, // row oid to find in table + mdb_pos inHintFromPos, // suggested hint regarding start position + mdb_pos inToPos, // desired new position for row inRowId + mdb_pos* outActualPos) = 0; // actual new position of row in table + + NS_IMETHOD MoveRow( // change position of row in unsorted table + nsIMdbEnv* ev, // context + nsIMdbRow* ioRow, // row oid to find in table + mdb_pos inHintFromPos, // suggested hint regarding start position + mdb_pos inToPos, // desired new position for row inRowId + mdb_pos* outActualPos) = 0; // actual new position of row in table + // } ----- end moving methods ----- + + // { ----- begin index methods ----- + NS_IMETHOD AddIndex( // create a sorting index for column if possible + nsIMdbEnv* ev, // context + mdb_column inColumn, // the column to sort by index + nsIMdbThumb** acqThumb) = + 0; // acquire thumb for incremental index building + // Call nsIMdbThumb::DoMore() until done, or until the thumb is broken, and + // then the index addition will be finished. + + NS_IMETHOD CutIndex( // stop supporting a specific column index + nsIMdbEnv* ev, // context + mdb_column inColumn, // the column with index to be removed + nsIMdbThumb** acqThumb) = + 0; // acquire thumb for incremental index destroy + // Call nsIMdbThumb::DoMore() until done, or until the thumb is broken, and + // then the index removal will be finished. + + NS_IMETHOD HasIndex( // query for current presence of a column index + nsIMdbEnv* ev, // context + mdb_column inColumn, // the column to investigate + mdb_bool* outHasIndex) = 0; // whether column has index for this column + + NS_IMETHOD EnableIndexOnSort( // create an index for col on first sort + nsIMdbEnv* ev, // context + mdb_column inColumn) = 0; // the column to index if ever sorted + + NS_IMETHOD QueryIndexOnSort( // check whether index on sort is enabled + nsIMdbEnv* ev, // context + mdb_column inColumn, // the column to investigate + mdb_bool* outIndexOnSort) = + 0; // whether column has index-on-sort enabled + + NS_IMETHOD DisableIndexOnSort( // prevent future index creation on sort + nsIMdbEnv* ev, // context + mdb_column inColumn) = 0; // the column to index if ever sorted + // } ----- end index methods ----- + + // } ===== end nsIMdbTable methods ===== +}; + +NS_DEFINE_STATIC_IID_ACCESSOR(nsIMdbTable, NS_IMDBTABLE_IID) + +/*| nsIMdbSorting: a view of a table in some particular sort order. This +**| row order closely resembles a readonly array of rows with the same row +**| membership as the underlying table, but in a different order than the +**| table's explicit row order. But the sorting's row membership changes +**| whenever the table's membership changes (without any notification, so +**| keep this in mind when modifying the table). +**| +**|| table: every sorting is associated with a particular table. You +**| cannot change which table is used by a sorting (just ask some new +**| table for a suitable sorting instance instead). +**| +**|| compare: the ordering method used by a sorting, wrapped up in a +**| abstract plug-in interface. When this was never installed by an +**| explicit call to SetNewCompare(), a compare object is still returned, +**| and it might match the compare instance returned by the factory method +**| nsIMdbFactory::MakeCompare(), which represents a default sort order +**| (which we fervently hope is consistently ASCII byte ordering). +**| +**|| cursor: in case callers are more comfortable with a cursor style +**| of accessing row members, each sorting will happily return a cursor +**| instance with behavior very similar to a cursor returned from a call +**| to nsIMdbTable::GetTableRowCursor(), but with different row order. +**| A cursor should show exactly the same information as the pos methods. +**| +**|| pos: the PosToOid() and PosToRow() methods are just like the table +**| methods of the same name, except they show rows in the sort order of +**| the sorting, rather than that of the table. These methods are like +**| readonly array position accessor's, or like a C++ operator[]. +|*/ +class nsIMdbSorting : public nsIMdbObject { // sorting of some table + public: + // { ===== begin nsIMdbSorting methods ===== + + // { ----- begin attribute methods ----- + // sorting: note all rows are assumed sorted by row ID as a secondary + // sort following the primary column sort, when table rows are sorted. + + NS_IMETHOD GetTable(nsIMdbEnv* ev, nsIMdbTable** acqTable) = 0; + NS_IMETHOD GetSortColumn( // query which col is currently sorted + nsIMdbEnv* ev, // context + mdb_column* outColumn) = 0; // col the table uses for sorting (or zero) + + // } ----- end attribute methods ----- + + // { ----- begin cursor methods ----- + NS_IMETHOD GetSortingRowCursor( // make a cursor, starting at inRowPos + nsIMdbEnv* ev, // context + mdb_pos inRowPos, // zero-based ordinal position of row in table + nsIMdbTableRowCursor** acqCursor) = 0; // acquire new cursor instance + // A cursor interface turning same info as PosToOid() or PosToRow(). + // } ----- end row position methods ----- + + // { ----- begin row position methods ----- + NS_IMETHOD PosToOid( // get row member for a table position + nsIMdbEnv* ev, // context + mdb_pos inRowPos, // zero-based ordinal position of row in table + mdbOid* outOid) = 0; // row oid at the specified position + + NS_IMETHOD PosToRow( // test for the table position of a row member + nsIMdbEnv* ev, // context + mdb_pos inRowPos, // zero-based ordinal position of row in table + nsIMdbRow** acqRow) = 0; // acquire row at table position inRowPos + // } ----- end row position methods ----- + + // } ===== end nsIMdbSorting methods ===== +}; + +/*| nsIMdbTableRowCursor: cursor class for iterating table rows +**| +**|| table: the cursor is associated with a specific table, which can be +**| set to a different table (which resets the position to -1 so the +**| next row acquired is the first in the table. +**| +**|| NextRowId: the rows in the table can be iterated by identity alone, +**| without actually reading the cells of any row with this method. +**| +**|| NextRowCells: read the next row in the table, but only read cells +**| from the table which are already present in the row (so no new cells +**| are added to the row, even if they are present in the table). All the +**| cells will have content specified, even it is the empty string. No +**| columns will be removed, even if missing from the row (because missing +**| and empty are semantically equivalent). +**| +**|| NextRowAllCells: read the next row in the table, and access all the +**| cells for this row in the table, adding any missing columns to the row +**| as needed until all cells are represented. All the +**| cells will have content specified, even it is the empty string. No +**| columns will be removed, even if missing from the row (because missing +**| and empty are semantically equivalent). +**| +|*/ + +#define NS_IMDBTABLEROWCURSOR_IID_STR = "4f325dad-0385-4b62-a992-c914ab93587e" + +#define NS_IMDBTABLEROWCURSOR_IID \ + { \ + 0x4f325dad, 0x0385, 0x4b62, { \ + 0xa9, 0x92, 0xc9, 0x14, 0xab, 0x93, 0x58, 0x7e \ + } \ + } + +class nsIMdbTableRowCursor : public nsISupports { // table row iterator + public: + NS_DECLARE_STATIC_IID_ACCESSOR(NS_IMDBTABLEROWCURSOR_IID) + + // { ===== begin nsIMdbTableRowCursor methods ===== + + // { ----- begin attribute methods ----- + // NS_IMETHOD SetTable(nsIMdbEnv* ev, nsIMdbTable* ioTable) = 0; // sets pos + // to -1 Method SetTable() cut and made obsolete in keeping with new sorting + // methods. + + NS_IMETHOD GetTable(nsIMdbEnv* ev, nsIMdbTable** acqTable) = 0; + // } ----- end attribute methods ----- + + // { ----- begin duplicate row removal methods ----- + NS_IMETHOD CanHaveDupRowMembers(nsIMdbEnv* ev, // cursor might hold dups? + mdb_bool* outCanHaveDups) = 0; + + NS_IMETHOD MakeUniqueCursor( // clone cursor, removing duplicate rows + nsIMdbEnv* ev, // context + nsIMdbTableRowCursor** acqCursor) = 0; // acquire clone with no dups + // Note that MakeUniqueCursor() is never necessary for a cursor which was + // created by table method nsIMdbTable::GetTableRowCursor(), because a table + // never contains the same row as a member more than once. However, a cursor + // created by table method nsIMdbTable::FindRowMatches() might contain the + // same row more than once, because the same row can generate a hit by more + // than one column with a matching string prefix. Note this method can + // return the very same cursor instance with just an incremented refcount, + // when the original cursor could not contain any duplicate rows (calling + // CanHaveDupRowMembers() shows this case on a false return). Otherwise + // this method returns a different cursor instance. Callers should not use + // this MakeUniqueCursor() method lightly, because it tends to defeat the + // purpose of lazy programming techniques, since it can force creation of + // an explicit row collection in a new cursor's representation, in order to + // inspect the row membership and remove any duplicates; this can have big + // impact if a collection holds tens of thousands of rows or more, when + // the original cursor with dups simply referenced rows indirectly by row + // position ranges, without using an explicit row set representation. + // Callers are encouraged to use nsIMdbCursor::GetCount() to determine + // whether the row collection is very large (tens of thousands), and to + // delay calling MakeUniqueCursor() when possible, until a user interface + // element actually demands the creation of an explicit set representation. + // } ----- end duplicate row removal methods ----- + + // { ----- begin oid iteration methods ----- + NS_IMETHOD NextRowOid( // get row id of next row in the table + nsIMdbEnv* ev, // context + mdbOid* outOid, // out row oid + mdb_pos* outRowPos) = 0; // zero-based position of the row in table + // } ----- end oid iteration methods ----- + + // { ----- begin row iteration methods ----- + NS_IMETHOD NextRow( // get row cells from table for cells already in row + nsIMdbEnv* ev, // context + nsIMdbRow** acqRow, // acquire next row in table + mdb_pos* outRowPos) = 0; // zero-based position of the row in table + + NS_IMETHOD PrevRowOid( // get row id of previous row in the table + nsIMdbEnv* ev, // context + mdbOid* outOid, // out row oid + mdb_pos* outRowPos) = 0; // zero-based position of the row in table + // } ----- end oid iteration methods ----- + + // { ----- begin row iteration methods ----- + NS_IMETHOD PrevRow( // get row cells from table for cells already in row + nsIMdbEnv* ev, // context + nsIMdbRow** acqRow, // acquire previous row in table + mdb_pos* outRowPos) = 0; // zero-based position of the row in table + + // } ----- end row iteration methods ----- + + // { ----- begin copy iteration methods ----- + // NS_IMETHOD NextRowCopy( // put row cells into sink only when already in + // sink + // nsIMdbEnv* ev, // context + // nsIMdbRow* ioSinkRow, // sink for row cells read from next row + // mdbOid* outOid, // out row oid + // mdb_pos* outRowPos) = 0; // zero-based position of the row in table + // + // NS_IMETHOD NextRowCopyAll( // put all row cells into sink, adding to sink + // nsIMdbEnv* ev, // context + // nsIMdbRow* ioSinkRow, // sink for row cells read from next row + // mdbOid* outOid, // out row oid + // mdb_pos* outRowPos) = 0; // zero-based position of the row in table + // } ----- end copy iteration methods ----- + + // } ===== end nsIMdbTableRowCursor methods ===== +}; + +NS_DEFINE_STATIC_IID_ACCESSOR(nsIMdbTableRowCursor, NS_IMDBTABLEROWCURSOR_IID) + +/*| nsIMdbRow: a collection of cells +**| +|*/ + +#define NS_IMDBROW_IID_STR "271e8d6e-183a-40e3-9f18-36913b4c7853" + +#define NS_IMDBROW_IID \ + { \ + 0x271e8d6e, 0x183a, 0x40e3, { \ + 0x9f, 0x18, 0x36, 0x91, 0x3b, 0x4c, 0x78, 0x53 \ + } \ + } + +class nsIMdbRow : public nsIMdbCollection { // cell tuple + public: + NS_DECLARE_STATIC_IID_ACCESSOR(NS_IMDBROW_IID) + // { ===== begin nsIMdbRow methods ===== + + // { ----- begin cursor methods ----- + NS_IMETHOD GetRowCellCursor( // make a cursor starting iteration at inCellPos + nsIMdbEnv* ev, // context + mdb_pos inCellPos, // zero-based ordinal position of cell in row + nsIMdbRowCellCursor** acqCursor) = 0; // acquire new cursor instance + // } ----- end cursor methods ----- + + // { ----- begin column methods ----- + NS_IMETHOD AddColumn( // make sure a particular column is inside row + nsIMdbEnv* ev, // context + mdb_column inColumn, // column to add + const mdbYarn* inYarn) = 0; // cell value to install + + NS_IMETHOD CutColumn( // make sure a column is absent from the row + nsIMdbEnv* ev, // context + mdb_column inColumn) = 0; // column to ensure absent from row + + NS_IMETHOD CutAllColumns( // remove all columns from the row + nsIMdbEnv* ev) = 0; // context + // } ----- end column methods ----- + + // { ----- begin cell methods ----- + NS_IMETHOD NewCell( // get cell for specified column, or add new one + nsIMdbEnv* ev, // context + mdb_column inColumn, // column to add + nsIMdbCell** acqCell) = 0; // cell column and value + + NS_IMETHOD AddCell( // copy a cell from another row to this row + nsIMdbEnv* ev, // context + const nsIMdbCell* inCell) = 0; // cell column and value + + NS_IMETHOD GetCell( // find a cell in this row + nsIMdbEnv* ev, // context + mdb_column inColumn, // column to find + nsIMdbCell** acqCell) = 0; // cell for specified column, or null + + NS_IMETHOD EmptyAllCells( // make all cells in row empty of content + nsIMdbEnv* ev) = 0; // context + // } ----- end cell methods ----- + + // { ----- begin row methods ----- + NS_IMETHOD AddRow( // add all cells in another row to this one + nsIMdbEnv* ev, // context + nsIMdbRow* ioSourceRow) = 0; // row to union with + + NS_IMETHOD SetRow( // make exact duplicate of another row + nsIMdbEnv* ev, // context + nsIMdbRow* ioSourceRow) = 0; // row to duplicate + // } ----- end row methods ----- + + // { ----- begin blob methods ----- + NS_IMETHOD SetCellYarn(nsIMdbEnv* ev, // synonym for AddColumn() + mdb_column inColumn, // column to write + const mdbYarn* inYarn) = 0; // reads from yarn slots + // make this text object contain content from the yarn's buffer + + NS_IMETHOD GetCellYarn(nsIMdbEnv* ev, + mdb_column inColumn, // column to read + mdbYarn* outYarn) = 0; // writes some yarn slots + // copy content into the yarn buffer, and update mYarn_Fill and mYarn_Form + + NS_IMETHOD AliasCellYarn(nsIMdbEnv* ev, + mdb_column inColumn, // column to alias + mdbYarn* outYarn) = 0; // writes ALL yarn slots + + NS_IMETHOD NextCellYarn(nsIMdbEnv* ev, // iterative version of GetCellYarn() + mdb_column* ioColumn, // next column to read + mdbYarn* outYarn) = 0; // writes some yarn slots + // copy content into the yarn buffer, and update mYarn_Fill and mYarn_Form + // + // The ioColumn argument is an inout parameter which initially contains the + // last column accessed and returns the next column corresponding to the + // content read into the yarn. Callers should start with a zero column + // value to say 'no previous column', which causes the first column to be + // read. Then the value returned in ioColumn is perfect for the next call + // to NextCellYarn(), since it will then be the previous column accessed. + // Callers need only examine the column token returned to see which cell + // in the row is being read into the yarn. When no more columns remain, + // and the iteration has ended, ioColumn will return a zero token again. + // So iterating over cells starts and ends with a zero column token. + + NS_IMETHOD SeekCellYarn( // resembles nsIMdbRowCellCursor::SeekCell() + nsIMdbEnv* ev, // context + mdb_pos inPos, // position of cell in row sequence + mdb_column* outColumn, // column for this particular cell + mdbYarn* outYarn) = 0; // writes some yarn slots + // copy content into the yarn buffer, and update mYarn_Fill and mYarn_Form + // Callers can pass nil for outYarn to indicate no interest in content, so + // only the outColumn value is returned. NOTE to subclasses: you must be + // able to ignore outYarn when the pointer is nil; please do not crash. + + // } ----- end blob methods ----- + + // } ===== end nsIMdbRow methods ===== +}; + +NS_DEFINE_STATIC_IID_ACCESSOR(nsIMdbRow, NS_IMDBROW_IID) + +/*| nsIMdbRowCellCursor: cursor class for iterating row cells +**| +**|| row: the cursor is associated with a specific row, which can be +**| set to a different row (which resets the position to -1 so the +**| next cell acquired is the first in the row. +**| +**|| NextCell: get the next cell in the row and return its position and +**| a new instance of a nsIMdbCell to represent this next cell. +|*/ + +#define NS_IMDBROWCELLCURSOR_IID_STR "b33371a7-5d63-4d10-85a8-e44dffe75c28" + +#define NS_IMDBROWCELLCURSOR_IID \ + { \ + 0x271e8d6e, 0x5d63, 0x4d10, { \ + 0x85, 0xa8, 0xe4, 0x4d, 0xff, 0xe7, 0x5c, 0x28 \ + } \ + } + +class nsIMdbRowCellCursor : public nsISupports { // cell collection iterator + public: + NS_DECLARE_STATIC_IID_ACCESSOR(NS_IMDBROWCELLCURSOR_IID) + // { ===== begin nsIMdbRowCellCursor methods ===== + + // { ----- begin attribute methods ----- + NS_IMETHOD SetRow(nsIMdbEnv* ev, nsIMdbRow* ioRow) = 0; // sets pos to -1 + NS_IMETHOD GetRow(nsIMdbEnv* ev, nsIMdbRow** acqRow) = 0; + // } ----- end attribute methods ----- + + // { ----- begin cell seeking methods ----- + NS_IMETHOD SeekCell(nsIMdbEnv* ev, // context + mdb_pos inPos, // position of cell in row sequence + mdb_column* outColumn, // column for this particular cell + nsIMdbCell** acqCell) = 0; // the cell at inPos + // } ----- end cell seeking methods ----- + + // { ----- begin cell iteration methods ----- + NS_IMETHOD NextCell( // get next cell in the row + nsIMdbEnv* ev, // context + nsIMdbCell** acqCell, // changes to the next cell in the iteration + mdb_column* outColumn, // column for this particular cell + mdb_pos* outPos) = 0; // position of cell in row sequence + + NS_IMETHOD PickNextCell( // get next cell in row within filter set + nsIMdbEnv* ev, // context + nsIMdbCell* ioCell, // changes to the next cell in the iteration + const mdbColumnSet* inFilterSet, // col set of actual caller interest + mdb_column* outColumn, // column for this particular cell + mdb_pos* outPos) = 0; // position of cell in row sequence + + // Note that inFilterSet should not have too many (many more than 10?) + // cols, since this might imply a potential excessive consumption of time + // over many cursor calls when looking for column and filter intersection. + // } ----- end cell iteration methods ----- + + // } ===== end nsIMdbRowCellCursor methods ===== +}; + +NS_DEFINE_STATIC_IID_ACCESSOR(nsIMdbRowCellCursor, NS_IMDBROWCELLCURSOR_IID) + +/*| nsIMdbBlob: a base class for objects composed mainly of byte sequence state. +**| (This provides a base class for nsIMdbCell, so that cells themselves can +**| be used to set state in another cell, without extracting a buffer.) +|*/ +class nsIMdbBlob : public nsISupports { // a string with associated charset + public: + // { ===== begin nsIMdbBlob methods ===== + + // { ----- begin attribute methods ----- + NS_IMETHOD SetBlob(nsIMdbEnv* ev, + nsIMdbBlob* ioBlob) = 0; // reads inBlob slots + // when inBlob is in the same suite, this might be fastest cell-to-cell + + NS_IMETHOD ClearBlob( // make empty (so content has zero length) + nsIMdbEnv* ev) = 0; + // clearing a yarn is like SetYarn() with empty yarn instance content + + NS_IMETHOD GetBlobFill(nsIMdbEnv* ev, + mdb_fill* outFill) = 0; // size of blob + // Same value that would be put into mYarn_Fill, if one called GetYarn() + // with a yarn instance that had mYarn_Buf==nil and mYarn_Size==0. + + NS_IMETHOD SetYarn(nsIMdbEnv* ev, + const mdbYarn* inYarn) = 0; // reads from yarn slots + // make this text object contain content from the yarn's buffer + + NS_IMETHOD GetYarn(nsIMdbEnv* ev, + mdbYarn* outYarn) = 0; // writes some yarn slots + // copy content into the yarn buffer, and update mYarn_Fill and mYarn_Form + + NS_IMETHOD AliasYarn(nsIMdbEnv* ev, + mdbYarn* outYarn) = 0; // writes ALL yarn slots + // AliasYarn() reveals sensitive internal text buffer state to the caller + // by setting mYarn_Buf to point into the guts of this text implementation. + // + // The caller must take great care to avoid writing on this space, and to + // avoid calling any method that would cause the state of this text object + // to change (say by directly or indirectly setting the text to hold more + // content that might grow the size of the buffer and free the old buffer). + // In particular, callers should scrupulously avoid making calls into the + // mdb interface to write any content while using the buffer pointer found + // in the returned yarn instance. Best safe usage involves copying content + // into some other kind of external content representation beyond mdb. + // + // (The original design of this method a week earlier included the concept + // of very fast and efficient cooperative locking via a pointer to some lock + // member slot. But let's ignore that complexity in the current design.) + // + // AliasYarn() is specifically intended as the first step in transferring + // content from nsIMdbBlob to a nsString representation, without forcing extra + // allocations and/or memory copies. (A standard nsIMdbBlob_AsString() utility + // will use AliasYarn() as the first step in setting a nsString instance.) + // + // This is an alternative to the GetYarn() method, which has copy semantics + // only; AliasYarn() relaxes a robust safety principle only for performance + // reasons, to accommodate the need for callers to transform text content to + // some other canonical representation that would necessitate an additional + // copy and transformation when such is incompatible with the mdbYarn format. + // + // The implementation of AliasYarn() should have extremely little overhead + // besides the virtual dispatch to the method implementation, and the code + // necessary to populate all the mdbYarn member slots with internal buffer + // address and metainformation that describes the buffer content. Note that + // mYarn_Grow must always be set to nil to indicate no resizing is allowed. + + // } ----- end attribute methods ----- + + // } ===== end nsIMdbBlob methods ===== +}; + +/*| nsIMdbCell: the text in a single column of a row. The base nsIMdbBlob +**| class provides all the interface related to accessing cell text. +**| +**|| column: each cell in a row appears in a specific column, where this +**| column is identified by the an integer mdb_scope value (generated by +**| the StringToScopeToken() method in the containing nsIMdbPort instance). +**| Because a row cannot have more than one cell with the same column, +**| something must give if one calls SetColumn() with an existing column +**| in the same row. When this happens, the other cell is replaced with +**| this cell (and the old cell is closed if it has outstanding refs). +**| +**|| row: every cell instance is a part of some row, and every cell knows +**| which row is the parent row. (Note this should be represented by a +**| weak backpointer, so that outstanding cell references cannot keep a +**| row open that should be closed. Otherwise we'd have ref graph cycles.) +**| +**|| text: a cell can either be text, or it can have a child row or table, +**| but not both at once. If text is read from a cell with a child, the text +**| content should be empty (for AliasYarn()) or a description of the type +**| of child (perhaps "mdb:cell:child:row" or "mdb:cell:child:table"). +**| +**|| child: a cell might reference another row or a table, rather than text. +**| The interface for putting and getting children rows and tables was first +**| defined in the nsIMdbTable interface, but then this was moved to this cell +**| interface as more natural. +|*/ + +#define NS_IMDBCELL_IID \ + { \ + 0xa3b62f71, 0xa181, 0x4a91, { \ + 0xb6, 0x6b, 0x27, 0x10, 0x9b, 0x88, 0x98, 0x35 \ + } \ + } + +#define NS_IMDBCELL_IID_STR = "a3b62f71-a181-4a91-b66b-27109b889835" + +class nsIMdbCell + : public nsIMdbBlob { // text attribute in row with column scope + public: + NS_DECLARE_STATIC_IID_ACCESSOR(NS_IMDBTABLEROWCURSOR_IID) + // { ===== begin nsIMdbCell methods ===== + + // { ----- begin attribute methods ----- + NS_IMETHOD SetColumn(nsIMdbEnv* ev, mdb_column inColumn) = 0; + NS_IMETHOD GetColumn(nsIMdbEnv* ev, mdb_column* outColumn) = 0; + + NS_IMETHOD GetCellInfo( // all cell metainfo except actual content + nsIMdbEnv* ev, + mdb_column* outColumn, // the column in the containing row + mdb_fill* outBlobFill, // the size of text content in bytes + mdbOid* outChildOid, // oid of possible row or table child + mdb_bool* outIsRowChild) = 0; // nonzero if child, and a row child + + // Checking all cell metainfo is a good way to avoid forcing a large cell + // in to memory when you don't actually want to use the content. + + NS_IMETHOD GetRow(nsIMdbEnv* ev, // parent row for this cell + nsIMdbRow** acqRow) = 0; + NS_IMETHOD GetPort(nsIMdbEnv* ev, // port containing cell + nsIMdbPort** acqPort) = 0; + // } ----- end attribute methods ----- + + // { ----- begin children methods ----- + NS_IMETHOD HasAnyChild( // does cell have a child instead of text? + nsIMdbEnv* ev, + mdbOid* outOid, // out id of row or table (or unbound if no child) + mdb_bool* outIsRow) = + 0; // nonzero if child is a row (rather than a table) + + NS_IMETHOD GetAnyChild( // access table of specific attribute + nsIMdbEnv* ev, // context + nsIMdbRow** acqRow, // child row (or null) + nsIMdbTable** acqTable) = 0; // child table (or null) + + NS_IMETHOD SetChildRow( // access table of specific attribute + nsIMdbEnv* ev, // context + nsIMdbRow* ioRow) = 0; // inRow must be bound inside this same db port + + NS_IMETHOD GetChildRow( // access row of specific attribute + nsIMdbEnv* ev, // context + nsIMdbRow** acqRow) = 0; // acquire child row (or nil if no child) + + NS_IMETHOD SetChildTable( // access table of specific attribute + nsIMdbEnv* ev, // context + nsIMdbTable* inTable) = + 0; // table must be bound inside this same db port + + NS_IMETHOD GetChildTable( // access table of specific attribute + nsIMdbEnv* ev, // context + nsIMdbTable** acqTable) = 0; // acquire child table (or nil if no child) + // } ----- end children methods ----- + + // } ===== end nsIMdbCell methods ===== +}; + +NS_DEFINE_STATIC_IID_ACCESSOR(nsIMdbCell, NS_IMDBTABLEROWCURSOR_IID) + +// } %%%%% end C++ abstract class interfaces %%%%% + +// 456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789 + +#endif /* _MDB_ */ |