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Diffstat (limited to 'ext/wasm/api/sqlite3-api-oo1.js')
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diff --git a/ext/wasm/api/sqlite3-api-oo1.js b/ext/wasm/api/sqlite3-api-oo1.js new file mode 100644 index 0000000..02ce9c0 --- /dev/null +++ b/ext/wasm/api/sqlite3-api-oo1.js @@ -0,0 +1,1800 @@ +/* + 2022-07-22 + + The author disclaims copyright to this source code. In place of a + legal notice, here is a blessing: + + * May you do good and not evil. + * May you find forgiveness for yourself and forgive others. + * May you share freely, never taking more than you give. + + *********************************************************************** + + This file contains the so-called OO #1 API wrapper for the sqlite3 + WASM build. It requires that sqlite3-api-glue.js has already run + and it installs its deliverable as self.sqlite3.oo1. +*/ +self.sqlite3ApiBootstrap.initializers.push(function(sqlite3){ + const toss = (...args)=>{throw new Error(args.join(' '))}; + const toss3 = (...args)=>{throw new sqlite3.SQLite3Error(...args)}; + + const capi = sqlite3.capi, wasm = sqlite3.wasm, util = sqlite3.util; + /* What follows is colloquially known as "OO API #1". It is a + binding of the sqlite3 API which is designed to be run within + the same thread (main or worker) as the one in which the + sqlite3 WASM binding was initialized. This wrapper cannot use + the sqlite3 binding if, e.g., the wrapper is in the main thread + and the sqlite3 API is in a worker. */ + + /** + In order to keep clients from manipulating, perhaps + inadvertently, the underlying pointer values of DB and Stmt + instances, we'll gate access to them via the `pointer` property + accessor and store their real values in this map. Keys = DB/Stmt + objects, values = pointer values. This also unifies how those are + accessed, for potential use downstream via custom + wasm.xWrap() function signatures which know how to extract + it. + */ + const __ptrMap = new WeakMap(); + /** + Map of DB instances to objects, each object being a map of Stmt + wasm pointers to Stmt objects. + */ + const __stmtMap = new WeakMap(); + + /** If object opts has _its own_ property named p then that + property's value is returned, else dflt is returned. */ + const getOwnOption = (opts, p, dflt)=>{ + const d = Object.getOwnPropertyDescriptor(opts,p); + return d ? d.value : dflt; + }; + + // Documented in DB.checkRc() + const checkSqlite3Rc = function(dbPtr, sqliteResultCode){ + if(sqliteResultCode){ + if(dbPtr instanceof DB) dbPtr = dbPtr.pointer; + toss3( + "sqlite result code",sqliteResultCode+":", + (dbPtr + ? capi.sqlite3_errmsg(dbPtr) + : capi.sqlite3_errstr(sqliteResultCode)) + ); + } + }; + + /** + sqlite3_trace_v2() callback which gets installed by the DB ctor + if its open-flags contain "t". + */ + const __dbTraceToConsole = + wasm.installFunction('i(ippp)', function(t,c,p,x){ + if(capi.SQLITE_TRACE_STMT===t){ + // x == SQL, p == sqlite3_stmt* + console.log("SQL TRACE #"+(++this.counter), + wasm.cstringToJs(x)); + } + }.bind({counter: 0})); + + /** + A map of sqlite3_vfs pointers to SQL code to run when the DB + constructor opens a database with the given VFS. + */ + const __vfsPostOpenSql = Object.create(null); + + /** + A proxy for DB class constructors. It must be called with the + being-construct DB object as its "this". See the DB constructor + for the argument docs. This is split into a separate function + in order to enable simple creation of special-case DB constructors, + e.g. JsStorageDb and OpfsDb. + + Expects to be passed a configuration object with the following + properties: + + - `.filename`: the db filename. It may be a special name like ":memory:" + or "". + + - `.flags`: as documented in the DB constructor. + + - `.vfs`: as documented in the DB constructor. + + It also accepts those as the first 3 arguments. + */ + const dbCtorHelper = function ctor(...args){ + if(!ctor._name2vfs){ + /** + Map special filenames which we handle here (instead of in C) + to some helpful metadata... + + As of 2022-09-20, the C API supports the names :localStorage: + and :sessionStorage: for kvvfs. However, C code cannot + determine (without embedded JS code, e.g. via Emscripten's + EM_JS()) whether the kvvfs is legal in the current browser + context (namely the main UI thread). In order to help client + code fail early on, instead of it being delayed until they + try to read or write a kvvfs-backed db, we'll check for those + names here and throw if they're not legal in the current + context. + */ + ctor._name2vfs = Object.create(null); + const isWorkerThread = ('function'===typeof importScripts/*===running in worker thread*/) + ? (n)=>toss3("The VFS for",n,"is only available in the main window thread.") + : false; + ctor._name2vfs[':localStorage:'] = { + vfs: 'kvvfs', filename: isWorkerThread || (()=>'local') + }; + ctor._name2vfs[':sessionStorage:'] = { + vfs: 'kvvfs', filename: isWorkerThread || (()=>'session') + }; + } + const opt = ctor.normalizeArgs(...args); + let fn = opt.filename, vfsName = opt.vfs, flagsStr = opt.flags; + if(('string'!==typeof fn && 'number'!==typeof fn) + || 'string'!==typeof flagsStr + || (vfsName && ('string'!==typeof vfsName && 'number'!==typeof vfsName))){ + console.error("Invalid DB ctor args",opt,arguments); + toss3("Invalid arguments for DB constructor."); + } + let fnJs = ('number'===typeof fn) ? wasm.cstringToJs(fn) : fn; + const vfsCheck = ctor._name2vfs[fnJs]; + if(vfsCheck){ + vfsName = vfsCheck.vfs; + fn = fnJs = vfsCheck.filename(fnJs); + } + let pDb, oflags = 0; + if( flagsStr.indexOf('c')>=0 ){ + oflags |= capi.SQLITE_OPEN_CREATE | capi.SQLITE_OPEN_READWRITE; + } + if( flagsStr.indexOf('w')>=0 ) oflags |= capi.SQLITE_OPEN_READWRITE; + if( 0===oflags ) oflags |= capi.SQLITE_OPEN_READONLY; + oflags |= capi.SQLITE_OPEN_EXRESCODE; + const stack = wasm.pstack.pointer; + try { + const pPtr = wasm.pstack.allocPtr() /* output (sqlite3**) arg */; + let rc = capi.sqlite3_open_v2(fn, pPtr, oflags, vfsName || 0); + pDb = wasm.getPtrValue(pPtr); + checkSqlite3Rc(pDb, rc); + if(flagsStr.indexOf('t')>=0){ + capi.sqlite3_trace_v2(pDb, capi.SQLITE_TRACE_STMT, + __dbTraceToConsole, 0); + } + // Check for per-VFS post-open SQL... + const pVfs = capi.sqlite3_js_db_vfs(pDb); + //console.warn("Opened db",fn,"with vfs",vfsName,pVfs); + if(!pVfs) toss3("Internal error: cannot get VFS for new db handle."); + const postInitSql = __vfsPostOpenSql[pVfs]; + if(postInitSql){ + rc = capi.sqlite3_exec(pDb, postInitSql, 0, 0, 0); + checkSqlite3Rc(pDb, rc); + } + }catch( e ){ + if( pDb ) capi.sqlite3_close_v2(pDb); + throw e; + }finally{ + wasm.pstack.restore(stack); + } + this.filename = fnJs; + __ptrMap.set(this, pDb); + __stmtMap.set(this, Object.create(null)); + }; + + /** + Sets SQL which should be exec()'d on a DB instance after it is + opened with the given VFS pointer. This is intended only for use + by DB subclasses or sqlite3_vfs implementations. + */ + dbCtorHelper.setVfsPostOpenSql = function(pVfs, sql){ + __vfsPostOpenSql[pVfs] = sql; + }; + + /** + A helper for DB constructors. It accepts either a single + config-style object or up to 3 arguments (filename, dbOpenFlags, + dbVfsName). It returns a new object containing: + + { filename: ..., flags: ..., vfs: ... } + + If passed an object, any additional properties it has are copied + as-is into the new object. + */ + dbCtorHelper.normalizeArgs = function(filename=':memory:',flags = 'c',vfs = null){ + const arg = {}; + if(1===arguments.length && 'object'===typeof arguments[0]){ + const x = arguments[0]; + Object.keys(x).forEach((k)=>arg[k] = x[k]); + if(undefined===arg.flags) arg.flags = 'c'; + if(undefined===arg.vfs) arg.vfs = null; + if(undefined===arg.filename) arg.filename = ':memory:'; + }else{ + arg.filename = filename; + arg.flags = flags; + arg.vfs = vfs; + } + return arg; + }; + /** + The DB class provides a high-level OO wrapper around an sqlite3 + db handle. + + The given db filename must be resolvable using whatever + filesystem layer (virtual or otherwise) is set up for the default + sqlite3 VFS. + + Note that the special sqlite3 db names ":memory:" and "" + (temporary db) have their normal special meanings here and need + not resolve to real filenames, but "" uses an on-storage + temporary database and requires that the VFS support that. + + The second argument specifies the open/create mode for the + database. It must be string containing a sequence of letters (in + any order, but case sensitive) specifying the mode: + + - "c": create if it does not exist, else fail if it does not + exist. Implies the "w" flag. + + - "w": write. Implies "r": a db cannot be write-only. + + - "r": read-only if neither "w" nor "c" are provided, else it + is ignored. + + - "t": enable tracing of SQL executed on this database handle, + sending it to `console.log()`. To disable it later, call + `sqlite3.capi.sqlite3_trace_v2(thisDb.pointer, 0, 0, 0)`. + + If "w" is not provided, the db is implicitly read-only, noting + that "rc" is meaningless + + Any other letters are currently ignored. The default is + "c". These modes are ignored for the special ":memory:" and "" + names and _may_ be ignored altogether for certain VFSes. + + The final argument is analogous to the final argument of + sqlite3_open_v2(): the name of an sqlite3 VFS. Pass a falsy value, + or none at all, to use the default. If passed a value, it must + be the string name of a VFS. + + The constructor optionally (and preferably) takes its arguments + in the form of a single configuration object with the following + properties: + + - `filename`: database file name + - `flags`: open-mode flags + - `vfs`: the VFS fname + + The `filename` and `vfs` arguments may be either JS strings or + C-strings allocated via WASM. `flags` is required to be a JS + string (because it's specific to this API, which is specific + to JS). + + For purposes of passing a DB instance to C-style sqlite3 + functions, the DB object's read-only `pointer` property holds its + `sqlite3*` pointer value. That property can also be used to check + whether this DB instance is still open. + + In the main window thread, the filenames `":localStorage:"` and + `":sessionStorage:"` are special: they cause the db to use either + localStorage or sessionStorage for storing the database using + the kvvfs. If one of these names are used, they trump + any vfs name set in the arguments. + */ + const DB = function(...args){ + dbCtorHelper.apply(this, args); + }; + DB.dbCtorHelper = dbCtorHelper; + + /** + Internal-use enum for mapping JS types to DB-bindable types. + These do not (and need not) line up with the SQLITE_type + values. All values in this enum must be truthy and distinct + but they need not be numbers. + */ + const BindTypes = { + null: 1, + number: 2, + string: 3, + boolean: 4, + blob: 5 + }; + BindTypes['undefined'] == BindTypes.null; + if(wasm.bigIntEnabled){ + BindTypes.bigint = BindTypes.number; + } + + /** + This class wraps sqlite3_stmt. Calling this constructor + directly will trigger an exception. Use DB.prepare() to create + new instances. + + For purposes of passing a Stmt instance to C-style sqlite3 + functions, its read-only `pointer` property holds its `sqlite3_stmt*` + pointer value. + + Other non-function properties include: + + - `db`: the DB object which created the statement. + + - `columnCount`: the number of result columns in the query, or 0 for + queries which cannot return results. + + - `parameterCount`: the number of bindable paramters in the query. + */ + const Stmt = function(){ + if(BindTypes!==arguments[2]){ + toss3("Do not call the Stmt constructor directly. Use DB.prepare()."); + } + this.db = arguments[0]; + __ptrMap.set(this, arguments[1]); + this.columnCount = capi.sqlite3_column_count(this.pointer); + this.parameterCount = capi.sqlite3_bind_parameter_count(this.pointer); + }; + + /** Throws if the given DB has been closed, else it is returned. */ + const affirmDbOpen = function(db){ + if(!db.pointer) toss3("DB has been closed."); + return db; + }; + + /** Throws if ndx is not an integer or if it is out of range + for stmt.columnCount, else returns stmt. + + Reminder: this will also fail after the statement is finalized + but the resulting error will be about an out-of-bounds column + index rather than a statement-is-finalized error. + */ + const affirmColIndex = function(stmt,ndx){ + if((ndx !== (ndx|0)) || ndx<0 || ndx>=stmt.columnCount){ + toss3("Column index",ndx,"is out of range."); + } + return stmt; + }; + + /** + Expects to be passed the `arguments` object from DB.exec(). Does + the argument processing/validation, throws on error, and returns + a new object on success: + + { sql: the SQL, opt: optionsObj, cbArg: function} + + The opt object is a normalized copy of any passed to this + function. The sql will be converted to a string if it is provided + in one of the supported non-string formats. + + cbArg is only set if the opt.callback or opt.resultRows are set, + in which case it's a function which expects to be passed the + current Stmt and returns the callback argument of the type + indicated by the input arguments. + */ + const parseExecArgs = function(db, args){ + const out = Object.create(null); + out.opt = Object.create(null); + switch(args.length){ + case 1: + if('string'===typeof args[0] || util.isSQLableTypedArray(args[0])){ + out.sql = args[0]; + }else if(Array.isArray(args[0])){ + out.sql = args[0]; + }else if(args[0] && 'object'===typeof args[0]){ + out.opt = args[0]; + out.sql = out.opt.sql; + } + break; + case 2: + out.sql = args[0]; + out.opt = args[1]; + break; + default: toss3("Invalid argument count for exec()."); + }; + out.sql = util.flexibleString(out.sql); + if('string'!==typeof out.sql){ + toss3("Missing SQL argument or unsupported SQL value type."); + } + const opt = out.opt; + switch(opt.returnValue){ + case 'resultRows': + if(!opt.resultRows) opt.resultRows = []; + out.returnVal = ()=>opt.resultRows; + break; + case 'saveSql': + if(!opt.saveSql) opt.saveSql = []; + out.returnVal = ()=>opt.saveSql; + break; + case undefined: + case 'this': + out.returnVal = ()=>db; + break; + default: + toss3("Invalid returnValue value:",opt.returnValue); + } + if(opt.callback || opt.resultRows){ + switch((undefined===opt.rowMode) + ? 'array' : opt.rowMode) { + case 'object': out.cbArg = (stmt)=>stmt.get(Object.create(null)); break; + case 'array': out.cbArg = (stmt)=>stmt.get([]); break; + case 'stmt': + if(Array.isArray(opt.resultRows)){ + toss3("exec(): invalid rowMode for a resultRows array: must", + "be one of 'array', 'object',", + "a result column number, or column name reference."); + } + out.cbArg = (stmt)=>stmt; + break; + default: + if(util.isInt32(opt.rowMode)){ + out.cbArg = (stmt)=>stmt.get(opt.rowMode); + break; + }else if('string'===typeof opt.rowMode && opt.rowMode.length>1){ + /* "$X", ":X", and "@X" fetch column named "X" (case-sensitive!) */ + const prefix = opt.rowMode[0]; + if(':'===prefix || '@'===prefix || '$'===prefix){ + out.cbArg = function(stmt){ + const rc = stmt.get(this.obj)[this.colName]; + return (undefined===rc) ? toss3("exec(): unknown result column:",this.colName) : rc; + }.bind({ + obj:Object.create(null), + colName: opt.rowMode.substr(1) + }); + break; + } + } + toss3("Invalid rowMode:",opt.rowMode); + } + } + return out; + }; + + /** + Internal impl of the DB.selectArray() and + selectObject() methods. + */ + const __selectFirstRow = (db, sql, bind, getArg)=>{ + let stmt, rc; + try { + stmt = db.prepare(sql).bind(bind); + if(stmt.step()) rc = stmt.get(getArg); + }finally{ + if(stmt) stmt.finalize(); + } + return rc; + }; + + /** + Expects to be given a DB instance or an `sqlite3*` pointer (may + be null) and an sqlite3 API result code. If the result code is + not falsy, this function throws an SQLite3Error with an error + message from sqlite3_errmsg(), using dbPtr as the db handle, or + sqlite3_errstr() if dbPtr is falsy. Note that if it's passed a + non-error code like SQLITE_ROW or SQLITE_DONE, it will still + throw but the error string might be "Not an error." The various + non-0 non-error codes need to be checked for in + client code where they are expected. + */ + DB.checkRc = checkSqlite3Rc; + + DB.prototype = { + /** Returns true if this db handle is open, else false. */ + isOpen: function(){ + return !!this.pointer; + }, + /** Throws if this given DB has been closed, else returns `this`. */ + affirmOpen: function(){ + return affirmDbOpen(this); + }, + /** + Finalizes all open statements and closes this database + connection. This is a no-op if the db has already been + closed. After calling close(), `this.pointer` will resolve to + `undefined`, so that can be used to check whether the db + instance is still opened. + + If this.onclose.before is a function then it is called before + any close-related cleanup. + + If this.onclose.after is a function then it is called after the + db is closed but before auxiliary state like this.filename is + cleared. + + Both onclose handlers are passed this object. If this db is not + opened, neither of the handlers are called. Any exceptions the + handlers throw are ignored because "destructors must not + throw." + + Note that garbage collection of a db handle, if it happens at + all, will never trigger close(), so onclose handlers are not a + reliable way to implement close-time cleanup or maintenance of + a db. + */ + close: function(){ + if(this.pointer){ + if(this.onclose && (this.onclose.before instanceof Function)){ + try{this.onclose.before(this)} + catch(e){/*ignore*/} + } + const pDb = this.pointer; + Object.keys(__stmtMap.get(this)).forEach((k,s)=>{ + if(s && s.pointer) s.finalize(); + }); + __ptrMap.delete(this); + __stmtMap.delete(this); + capi.sqlite3_close_v2(pDb); + if(this.onclose && (this.onclose.after instanceof Function)){ + try{this.onclose.after(this)} + catch(e){/*ignore*/} + } + delete this.filename; + } + }, + /** + Returns the number of changes, as per sqlite3_changes() + (if the first argument is false) or sqlite3_total_changes() + (if it's true). If the 2nd argument is true, it uses + sqlite3_changes64() or sqlite3_total_changes64(), which + will trigger an exception if this build does not have + BigInt support enabled. + */ + changes: function(total=false,sixtyFour=false){ + const p = affirmDbOpen(this).pointer; + if(total){ + return sixtyFour + ? capi.sqlite3_total_changes64(p) + : capi.sqlite3_total_changes(p); + }else{ + return sixtyFour + ? capi.sqlite3_changes64(p) + : capi.sqlite3_changes(p); + } + }, + /** + Similar to the this.filename but returns the + sqlite3_db_filename() value for the given database name, + defaulting to "main". The argument may be either a JS string + or a pointer to a WASM-allocated C-string. + */ + dbFilename: function(dbName='main'){ + return capi.sqlite3_db_filename(affirmDbOpen(this).pointer, dbName); + }, + /** + Returns the name of the given 0-based db number, as documented + for sqlite3_db_name(). + */ + dbName: function(dbNumber=0){ + return capi.sqlite3_db_name(affirmDbOpen(this).pointer, dbNumber); + }, + /** + Returns the name of the sqlite3_vfs used by the given database + of this connection (defaulting to 'main'). The argument may be + either a JS string or a WASM C-string. Returns undefined if the + given db name is invalid. Throws if this object has been + close()d. + */ + dbVfsName: function(dbName=0){ + let rc; + const pVfs = capi.sqlite3_js_db_vfs( + affirmDbOpen(this).pointer, dbName + ); + if(pVfs){ + const v = new capi.sqlite3_vfs(pVfs); + try{ rc = wasm.cstringToJs(v.$zName) } + finally { v.dispose() } + } + return rc; + }, + /** + Compiles the given SQL and returns a prepared Stmt. This is + the only way to create new Stmt objects. Throws on error. + + The given SQL must be a string, a Uint8Array holding SQL, a + WASM pointer to memory holding the NUL-terminated SQL string, + or an array of strings. In the latter case, the array is + concatenated together, with no separators, to form the SQL + string (arrays are often a convenient way to formulate long + statements). If the SQL contains no statements, an + SQLite3Error is thrown. + + Design note: the C API permits empty SQL, reporting it as a 0 + result code and a NULL stmt pointer. Supporting that case here + would cause extra work for all clients: any use of the Stmt API + on such a statement will necessarily throw, so clients would be + required to check `stmt.pointer` after calling `prepare()` in + order to determine whether the Stmt instance is empty or not. + Long-time practice (with other sqlite3 script bindings) + suggests that the empty-prepare case is sufficiently rare that + supporting it here would simply hurt overall usability. + */ + prepare: function(sql){ + affirmDbOpen(this); + const stack = wasm.pstack.pointer; + let ppStmt, pStmt; + try{ + ppStmt = wasm.pstack.alloc(8)/* output (sqlite3_stmt**) arg */; + DB.checkRc(this, capi.sqlite3_prepare_v2(this.pointer, sql, -1, ppStmt, null)); + pStmt = wasm.getPtrValue(ppStmt); + } + finally { + wasm.pstack.restore(stack); + } + if(!pStmt) toss3("Cannot prepare empty SQL."); + const stmt = new Stmt(this, pStmt, BindTypes); + __stmtMap.get(this)[pStmt] = stmt; + return stmt; + }, + /** + Executes one or more SQL statements in the form of a single + string. Its arguments must be either (sql,optionsObject) or + (optionsObject). In the latter case, optionsObject.sql must + contain the SQL to execute. By default it returns this object + but that can be changed via the `returnValue` option as + described below. Throws on error. + + If no SQL is provided, or a non-string is provided, an + exception is triggered. Empty SQL, on the other hand, is + simply a no-op. + + The optional options object may contain any of the following + properties: + + - `sql` = the SQL to run (unless it's provided as the first + argument). This must be of type string, Uint8Array, or an array + of strings. In the latter case they're concatenated together + as-is, _with no separator_ between elements, before evaluation. + The array form is often simpler for long hand-written queries. + + - `bind` = a single value valid as an argument for + Stmt.bind(). This is _only_ applied to the _first_ non-empty + statement in the SQL which has any bindable parameters. (Empty + statements are skipped entirely.) + + - `saveSql` = an optional array. If set, the SQL of each + executed statement is appended to this array before the + statement is executed (but after it is prepared - we don't have + the string until after that). Empty SQL statements are elided + but can have odd effects in the output. e.g. SQL of: `"select + 1; -- empty\n; select 2"` will result in an array containing + `["select 1;", "--empty \n; select 2"]`. That's simply how + sqlite3 records the SQL for the 2nd statement. + + ================================================================== + The following options apply _only_ to the _first_ statement + which has a non-zero result column count, regardless of whether + the statement actually produces any result rows. + ================================================================== + + - `columnNames`: if this is an array, the column names of the + result set are stored in this array before the callback (if + any) is triggered (regardless of whether the query produces any + result rows). If no statement has result columns, this value is + unchanged. Achtung: an SQL result may have multiple columns + with identical names. + + - `callback` = a function which gets called for each row of + the result set, but only if that statement has any result + _rows_. The callback's "this" is the options object, noting + that this function synthesizes one if the caller does not pass + one to exec(). The second argument passed to the callback is + always the current Stmt object, as it's needed if the caller + wants to fetch the column names or some such (noting that they + could also be fetched via `this.columnNames`, if the client + provides the `columnNames` option). + + ACHTUNG: The callback MUST NOT modify the Stmt object. Calling + any of the Stmt.get() variants, Stmt.getColumnName(), or + similar, is legal, but calling step() or finalize() is + not. Member methods which are illegal in this context will + trigger an exception. + + The first argument passed to the callback defaults to an array of + values from the current result row but may be changed with ... + + - `rowMode` = specifies the type of he callback's first argument. + It may be any of... + + A) A string describing what type of argument should be passed + as the first argument to the callback: + + A.1) `'array'` (the default) causes the results of + `stmt.get([])` to be passed to the `callback` and/or appended + to `resultRows` + + A.2) `'object'` causes the results of + `stmt.get(Object.create(null))` to be passed to the + `callback` and/or appended to `resultRows`. Achtung: an SQL + result may have multiple columns with identical names. In + that case, the right-most column will be the one set in this + object! + + A.3) `'stmt'` causes the current Stmt to be passed to the + callback, but this mode will trigger an exception if + `resultRows` is an array because appending the statement to + the array would be downright unhelpful. + + B) An integer, indicating a zero-based column in the result + row. Only that one single value will be passed on. + + C) A string with a minimum length of 2 and leading character of + ':', '$', or '@' will fetch the row as an object, extract that + one field, and pass that field's value to the callback. Note + that these keys are case-sensitive so must match the case used + in the SQL. e.g. `"select a A from t"` with a `rowMode` of + `'$A'` would work but `'$a'` would not. A reference to a column + not in the result set will trigger an exception on the first + row (as the check is not performed until rows are fetched). + Note also that `$` is a legal identifier character in JS so + need not be quoted. (Design note: those 3 characters were + chosen because they are the characters support for naming bound + parameters.) + + Any other `rowMode` value triggers an exception. + + - `resultRows`: if this is an array, it functions similarly to + the `callback` option: each row of the result set (if any), + with the exception that the `rowMode` 'stmt' is not legal. It + is legal to use both `resultRows` and `callback`, but + `resultRows` is likely much simpler to use for small data sets + and can be used over a WebWorker-style message interface. + exec() throws if `resultRows` is set and `rowMode` is 'stmt'. + + - `returnValue`: is a string specifying what this function + should return: + + A) The default value is `"this"`, meaning that the + DB object itself should be returned. + + B) `"resultRows"` means to return the value of the + `resultRows` option. If `resultRows` is not set, this + function behaves as if it were set to an empty array. + + C) `"saveSql"` means to return the value of the + `saveSql` option. If `saveSql` is not set, this + function behaves as if it were set to an empty array. + + Potential TODOs: + + - `bind`: permit an array of arrays/objects to bind. The first + sub-array would act on the first statement which has bindable + parameters (as it does now). The 2nd would act on the next such + statement, etc. + + - `callback` and `resultRows`: permit an array entries with + semantics similar to those described for `bind` above. + + */ + exec: function(/*(sql [,obj]) || (obj)*/){ + affirmDbOpen(this); + const arg = parseExecArgs(this, arguments); + if(!arg.sql){ + return toss3("exec() requires an SQL string."); + } + const opt = arg.opt; + const callback = opt.callback; + const resultRows = + Array.isArray(opt.resultRows) ? opt.resultRows : undefined; + let stmt; + let bind = opt.bind; + let evalFirstResult = !!(arg.cbArg || opt.columnNames) /* true to evaluate the first result-returning query */; + const stack = wasm.scopedAllocPush(); + try{ + const isTA = util.isSQLableTypedArray(arg.sql) + /* Optimization: if the SQL is a TypedArray we can save some string + conversion costs. */; + /* Allocate the two output pointers (ppStmt, pzTail) and heap + space for the SQL (pSql). When prepare_v2() returns, pzTail + will point to somewhere in pSql. */ + let sqlByteLen = isTA ? arg.sql.byteLength : wasm.jstrlen(arg.sql); + const ppStmt = wasm.scopedAlloc(/* output (sqlite3_stmt**) arg and pzTail */ + (2 * wasm.ptrSizeof) + + (sqlByteLen + 1/* SQL + NUL */)); + const pzTail = ppStmt + wasm.ptrSizeof /* final arg to sqlite3_prepare_v2() */; + let pSql = pzTail + wasm.ptrSizeof; + const pSqlEnd = pSql + sqlByteLen; + if(isTA) wasm.heap8().set(arg.sql, pSql); + else wasm.jstrcpy(arg.sql, wasm.heap8(), pSql, sqlByteLen, false); + wasm.setMemValue(pSql + sqlByteLen, 0/*NUL terminator*/); + while(pSql && wasm.getMemValue(pSql, 'i8') + /* Maintenance reminder:^^^ _must_ be 'i8' or else we + will very likely cause an endless loop. What that's + doing is checking for a terminating NUL byte. If we + use i32 or similar then we read 4 bytes, read stuff + around the NUL terminator, and get stuck in and + endless loop at the end of the SQL, endlessly + re-preparing an empty statement. */ ){ + wasm.setPtrValue(ppStmt, 0); + wasm.setPtrValue(pzTail, 0); + DB.checkRc(this, capi.sqlite3_prepare_v3( + this.pointer, pSql, sqlByteLen, 0, ppStmt, pzTail + )); + const pStmt = wasm.getPtrValue(ppStmt); + pSql = wasm.getPtrValue(pzTail); + sqlByteLen = pSqlEnd - pSql; + if(!pStmt) continue; + if(Array.isArray(opt.saveSql)){ + opt.saveSql.push(capi.sqlite3_sql(pStmt).trim()); + } + stmt = new Stmt(this, pStmt, BindTypes); + if(bind && stmt.parameterCount){ + stmt.bind(bind); + bind = null; + } + if(evalFirstResult && stmt.columnCount){ + /* Only forward SELECT results for the FIRST query + in the SQL which potentially has them. */ + evalFirstResult = false; + if(Array.isArray(opt.columnNames)){ + stmt.getColumnNames(opt.columnNames); + } + while(!!arg.cbArg && stmt.step()){ + stmt._isLocked = true; + const row = arg.cbArg(stmt); + if(resultRows) resultRows.push(row); + if(callback) callback.call(opt, row, stmt); + stmt._isLocked = false; + } + }else{ + stmt.step(); + } + stmt.finalize(); + stmt = null; + } + }/*catch(e){ + console.warn("DB.exec() is propagating exception",opt,e); + throw e; + }*/finally{ + if(stmt){ + delete stmt._isLocked; + stmt.finalize(); + } + wasm.scopedAllocPop(stack); + } + return arg.returnVal(); + }/*exec()*/, + /** + Creates a new scalar UDF (User-Defined Function) which is + accessible via SQL code. This function may be called in any + of the following forms: + + - (name, function) + - (name, function, optionsObject) + - (name, optionsObject) + - (optionsObject) + + In the final two cases, the function must be defined as the + `callback` property of the options object (optionally called + `xFunc` to align with the C API documentation). In the final + case, the function's name must be the 'name' property. + + The first two call forms can only be used for creating scalar + functions. Creating an aggregate or window function requires + the options-object form (see below for details). + + UDFs cannot currently be removed from a DB handle after they're + added. More correctly, they can be removed as documented for + sqlite3_create_function_v2(), but doing so will "leak" the + JS-created WASM binding of those functions. + + On success, returns this object. Throws on error. + + When called from SQL arguments to the UDF, and its result, + will be converted between JS and SQL with as much fidelity as + is feasible, triggering an exception if a type conversion + cannot be determined. The docs for sqlite3_create_function_v2() + describe the conversions in more detail. + + The values set in the options object differ for scalar and + aggregate functions: + + - Scalar: set the `xFunc` function-type property to the UDF + function. + + - Aggregate: set the `xStep` and `xFinal` function-type + properties to the "step" and "final" callbacks for the + aggregate. Do not set the `xFunc` property. + + - Window: set the `xStep`, `xFinal`, `xValue`, and `xInverse` + function-type properties. Do not set the `xFunc` property. + + The options object may optionally have an `xDestroy` + function-type property, as per sqlite3_create_function_v2(). + Its argument will be the WASM-pointer-type value of the `pApp` + property, and this function will throw if `pApp` is defined but + is not null, undefined, or a numeric (WASM pointer) + value. i.e. `pApp`, if set, must be value suitable for use as a + WASM pointer argument, noting that `null` or `undefined` will + translate to 0 for that purpose. + + The options object may contain flags to modify how + the function is defined: + + - `arity`: the number of arguments which SQL calls to this + function expect or require. The default value is `xFunc.length` + or `xStep.length` (i.e. the number of declared parameters it + has) **MINUS 1** (see below for why). As a special case, if the + `length` is 0, its arity is also 0 instead of -1. A negative + arity value means that the function is variadic and may accept + any number of arguments, up to sqlite3's compile-time + limits. sqlite3 will enforce the argument count if is zero or + greater. The callback always receives a pointer to an + `sqlite3_context` object as its first argument. Any arguments + after that are from SQL code. The leading context argument does + _not_ count towards the function's arity. See the docs for + sqlite3.capi.sqlite3_create_function_v2() for why that argument + is needed in the interface. + + The following options-object properties correspond to flags + documented at: + + https://sqlite.org/c3ref/create_function.html + + - `deterministic` = sqlite3.capi.SQLITE_DETERMINISTIC + - `directOnly` = sqlite3.capi.SQLITE_DIRECTONLY + - `innocuous` = sqlite3.capi.SQLITE_INNOCUOUS + + Sidebar: the ability to add new WASM-accessible functions to + the runtime requires that the WASM build is compiled with the + equivalent functionality as that provided by Emscripten's + `-sALLOW_TABLE_GROWTH` flag. + */ + createFunction: function f(name, xFunc, opt){ + const isFunc = (f)=>(f instanceof Function); + switch(arguments.length){ + case 1: /* (optionsObject) */ + opt = name; + name = opt.name; + xFunc = opt.xFunc || 0; + break; + case 2: /* (name, callback|optionsObject) */ + if(!isFunc(xFunc)){ + opt = xFunc; + xFunc = opt.xFunc || 0; + } + break; + case 3: /* name, xFunc, opt */ + break; + default: break; + } + if(!opt) opt = {}; + if('string' !== typeof name){ + toss3("Invalid arguments: missing function name."); + } + let xStep = opt.xStep || 0; + let xFinal = opt.xFinal || 0; + const xValue = opt.xValue || 0; + const xInverse = opt.xInverse || 0; + let isWindow = undefined; + if(isFunc(xFunc)){ + isWindow = false; + if(isFunc(xStep) || isFunc(xFinal)){ + toss3("Ambiguous arguments: scalar or aggregate?"); + } + xStep = xFinal = null; + }else if(isFunc(xStep)){ + if(!isFunc(xFinal)){ + toss3("Missing xFinal() callback for aggregate or window UDF."); + } + xFunc = null; + }else if(isFunc(xFinal)){ + toss3("Missing xStep() callback for aggregate or window UDF."); + }else{ + toss3("Missing function-type properties."); + } + if(false === isWindow){ + if(isFunc(xValue) || isFunc(xInverse)){ + toss3("xValue and xInverse are not permitted for non-window UDFs."); + } + }else if(isFunc(xValue)){ + if(!isFunc(xInverse)){ + toss3("xInverse must be provided if xValue is."); + } + isWindow = true; + }else if(isFunc(xInverse)){ + toss3("xValue must be provided if xInverse is."); + } + const pApp = opt.pApp; + if(undefined!==pApp && + null!==pApp && + (('number'!==typeof pApp) || !util.isInt32(pApp))){ + toss3("Invalid value for pApp property. Must be a legal WASM pointer value."); + } + const xDestroy = opt.xDestroy || 0; + if(xDestroy && !isFunc(xDestroy)){ + toss3("xDestroy property must be a function."); + } + let fFlags = 0 /*flags for sqlite3_create_function_v2()*/; + if(getOwnOption(opt, 'deterministic')) fFlags |= capi.SQLITE_DETERMINISTIC; + if(getOwnOption(opt, 'directOnly')) fFlags |= capi.SQLITE_DIRECTONLY; + if(getOwnOption(opt, 'innocuous')) fFlags |= capi.SQLITE_INNOCUOUS; + name = name.toLowerCase(); + const xArity = xFunc || xStep; + const arity = getOwnOption(opt, 'arity'); + const arityArg = ('number'===typeof arity + ? arity + : (xArity.length ? xArity.length-1/*for pCtx arg*/ : 0)); + let rc; + if( isWindow ){ + rc = capi.sqlite3_create_window_function( + this.pointer, name, arityArg, + capi.SQLITE_UTF8 | fFlags, pApp || 0, + xStep, xFinal, xValue, xInverse, xDestroy); + }else{ + rc = capi.sqlite3_create_function_v2( + this.pointer, name, arityArg, + capi.SQLITE_UTF8 | fFlags, pApp || 0, + xFunc, xStep, xFinal, xDestroy); + } + DB.checkRc(this, rc); + return this; + }/*createFunction()*/, + /** + Prepares the given SQL, step()s it one time, and returns + the value of the first result column. If it has no results, + undefined is returned. + + If passed a second argument, it is treated like an argument + to Stmt.bind(), so may be any type supported by that + function. Passing the undefined value is the same as passing + no value, which is useful when... + + If passed a 3rd argument, it is expected to be one of the + SQLITE_{typename} constants. Passing the undefined value is + the same as not passing a value. + + Throws on error (e.g. malformed SQL). + */ + selectValue: function(sql,bind,asType){ + let stmt, rc; + try { + stmt = this.prepare(sql).bind(bind); + if(stmt.step()) rc = stmt.get(0,asType); + }finally{ + if(stmt) stmt.finalize(); + } + return rc; + }, + /** + Prepares the given SQL, step()s it one time, and returns an + array containing the values of the first result row. If it has + no results, `undefined` is returned. + + If passed a second argument other than `undefined`, it is + treated like an argument to Stmt.bind(), so may be any type + supported by that function. + + Throws on error (e.g. malformed SQL). + */ + selectArray: function(sql,bind){ + return __selectFirstRow(this, sql, bind, []); + }, + + /** + Prepares the given SQL, step()s it one time, and returns an + object containing the key/value pairs of the first result + row. If it has no results, `undefined` is returned. + + Note that the order of returned object's keys is not guaranteed + to be the same as the order of the fields in the query string. + + If passed a second argument other than `undefined`, it is + treated like an argument to Stmt.bind(), so may be any type + supported by that function. + + Throws on error (e.g. malformed SQL). + */ + selectObject: function(sql,bind){ + return __selectFirstRow(this, sql, bind, {}); + }, + + /** + Returns the number of currently-opened Stmt handles for this db + handle, or 0 if this DB instance is closed. + */ + openStatementCount: function(){ + return this.pointer ? Object.keys(__stmtMap.get(this)).length : 0; + }, + + /** + Starts a transaction, calls the given callback, and then either + rolls back or commits the savepoint, depending on whether the + callback throws. The callback is passed this db object as its + only argument. On success, returns the result of the + callback. Throws on error. + + Note that transactions may not be nested, so this will throw if + it is called recursively. For nested transactions, use the + savepoint() method or manually manage SAVEPOINTs using exec(). + */ + transaction: function(callback){ + affirmDbOpen(this).exec("BEGIN"); + try { + const rc = callback(this); + this.exec("COMMIT"); + return rc; + }catch(e){ + this.exec("ROLLBACK"); + throw e; + } + }, + + /** + This works similarly to transaction() but uses sqlite3's SAVEPOINT + feature. This function starts a savepoint (with an unspecified name) + and calls the given callback function, passing it this db object. + If the callback returns, the savepoint is released (committed). If + the callback throws, the savepoint is rolled back. If it does not + throw, it returns the result of the callback. + */ + savepoint: function(callback){ + affirmDbOpen(this).exec("SAVEPOINT oo1"); + try { + const rc = callback(this); + this.exec("RELEASE oo1"); + return rc; + }catch(e){ + this.exec("ROLLBACK to SAVEPOINT oo1; RELEASE SAVEPOINT oo1"); + throw e; + } + } + }/*DB.prototype*/; + + + /** Throws if the given Stmt has been finalized, else stmt is + returned. */ + const affirmStmtOpen = function(stmt){ + if(!stmt.pointer) toss3("Stmt has been closed."); + return stmt; + }; + + /** Returns an opaque truthy value from the BindTypes + enum if v's type is a valid bindable type, else + returns a falsy value. As a special case, a value of + undefined is treated as a bind type of null. */ + const isSupportedBindType = function(v){ + let t = BindTypes[(null===v||undefined===v) ? 'null' : typeof v]; + switch(t){ + case BindTypes.boolean: + case BindTypes.null: + case BindTypes.number: + case BindTypes.string: + return t; + case BindTypes.bigint: + if(wasm.bigIntEnabled) return t; + /* else fall through */ + default: + //console.log("isSupportedBindType",t,v); + return util.isBindableTypedArray(v) ? BindTypes.blob : undefined; + } + }; + + /** + If isSupportedBindType(v) returns a truthy value, this + function returns that value, else it throws. + */ + const affirmSupportedBindType = function(v){ + //console.log('affirmSupportedBindType',v); + return isSupportedBindType(v) || toss3("Unsupported bind() argument type:",typeof v); + }; + + /** + If key is a number and within range of stmt's bound parameter + count, key is returned. + + If key is not a number then it is checked against named + parameters. If a match is found, its index is returned. + + Else it throws. + */ + const affirmParamIndex = function(stmt,key){ + const n = ('number'===typeof key) + ? key : capi.sqlite3_bind_parameter_index(stmt.pointer, key); + if(0===n || !util.isInt32(n)){ + toss3("Invalid bind() parameter name: "+key); + } + else if(n<1 || n>stmt.parameterCount) toss3("Bind index",key,"is out of range."); + return n; + }; + + /** + If stmt._isLocked is truthy, this throws an exception + complaining that the 2nd argument (an operation name, + e.g. "bind()") is not legal while the statement is "locked". + Locking happens before an exec()-like callback is passed a + statement, to ensure that the callback does not mutate or + finalize the statement. If it does not throw, it returns stmt. + */ + const affirmUnlocked = function(stmt,currentOpName){ + if(stmt._isLocked){ + toss3("Operation is illegal when statement is locked:",currentOpName); + } + return stmt; + }; + + /** + Binds a single bound parameter value on the given stmt at the + given index (numeric or named) using the given bindType (see + the BindTypes enum) and value. Throws on error. Returns stmt on + success. + */ + const bindOne = function f(stmt,ndx,bindType,val){ + affirmUnlocked(stmt, 'bind()'); + if(!f._){ + f._tooBigInt = (v)=>toss3( + "BigInt value is too big to store without precision loss:", v + ); + /* Reminder: when not in BigInt mode, it's impossible for + JS to represent a number out of the range we can bind, + so we have no range checking. */ + f._ = { + string: function(stmt, ndx, val, asBlob){ + if(1){ + /* _Hypothetically_ more efficient than the impl in the 'else' block. */ + const stack = wasm.scopedAllocPush(); + try{ + const n = wasm.jstrlen(val); + const pStr = wasm.scopedAlloc(n); + wasm.jstrcpy(val, wasm.heap8u(), pStr, n, false); + const f = asBlob ? capi.sqlite3_bind_blob : capi.sqlite3_bind_text; + return f(stmt.pointer, ndx, pStr, n, capi.SQLITE_TRANSIENT); + }finally{ + wasm.scopedAllocPop(stack); + } + }else{ + const bytes = wasm.jstrToUintArray(val,false); + const pStr = wasm.alloc(bytes.length || 1); + wasm.heap8u().set(bytes.length ? bytes : [0], pStr); + try{ + const f = asBlob ? capi.sqlite3_bind_blob : capi.sqlite3_bind_text; + return f(stmt.pointer, ndx, pStr, bytes.length, capi.SQLITE_TRANSIENT); + }finally{ + wasm.dealloc(pStr); + } + } + } + }; + }/* static init */ + affirmSupportedBindType(val); + ndx = affirmParamIndex(stmt,ndx); + let rc = 0; + switch((null===val || undefined===val) ? BindTypes.null : bindType){ + case BindTypes.null: + rc = capi.sqlite3_bind_null(stmt.pointer, ndx); + break; + case BindTypes.string: + rc = f._.string(stmt, ndx, val, false); + break; + case BindTypes.number: { + let m; + if(util.isInt32(val)) m = capi.sqlite3_bind_int; + else if('bigint'===typeof val){ + if(!util.bigIntFits64(val)){ + f._tooBigInt(val); + }else if(wasm.bigIntEnabled){ + m = capi.sqlite3_bind_int64; + }else if(util.bigIntFitsDouble(val)){ + val = Number(val); + m = capi.sqlite3_bind_double; + }else{ + f._tooBigInt(val); + } + }else{ // !int32, !bigint + val = Number(val); + if(wasm.bigIntEnabled && Number.isInteger(val)){ + m = capi.sqlite3_bind_int64; + }else{ + m = capi.sqlite3_bind_double; + } + } + rc = m(stmt.pointer, ndx, val); + break; + } + case BindTypes.boolean: + rc = capi.sqlite3_bind_int(stmt.pointer, ndx, val ? 1 : 0); + break; + case BindTypes.blob: { + if('string'===typeof val){ + rc = f._.string(stmt, ndx, val, true); + }else if(!util.isBindableTypedArray(val)){ + toss3("Binding a value as a blob requires", + "that it be a string, Uint8Array, or Int8Array."); + }else if(1){ + /* _Hypothetically_ more efficient than the impl in the 'else' block. */ + const stack = wasm.scopedAllocPush(); + try{ + const pBlob = wasm.scopedAlloc(val.byteLength || 1); + wasm.heap8().set(val.byteLength ? val : [0], pBlob) + rc = capi.sqlite3_bind_blob(stmt.pointer, ndx, pBlob, val.byteLength, + capi.SQLITE_TRANSIENT); + }finally{ + wasm.scopedAllocPop(stack); + } + }else{ + const pBlob = wasm.allocFromTypedArray(val); + try{ + rc = capi.sqlite3_bind_blob(stmt.pointer, ndx, pBlob, val.byteLength, + capi.SQLITE_TRANSIENT); + }finally{ + wasm.dealloc(pBlob); + } + } + break; + } + default: + console.warn("Unsupported bind() argument type:",val); + toss3("Unsupported bind() argument type: "+(typeof val)); + } + if(rc) DB.checkRc(stmt.db.pointer, rc); + return stmt; + }; + + Stmt.prototype = { + /** + "Finalizes" this statement. This is a no-op if the + statement has already been finalizes. Returns + undefined. Most methods in this class will throw if called + after this is. + */ + finalize: function(){ + if(this.pointer){ + affirmUnlocked(this,'finalize()'); + delete __stmtMap.get(this.db)[this.pointer]; + capi.sqlite3_finalize(this.pointer); + __ptrMap.delete(this); + delete this._mayGet; + delete this.columnCount; + delete this.parameterCount; + delete this.db; + delete this._isLocked; + } + }, + /** Clears all bound values. Returns this object. + Throws if this statement has been finalized. */ + clearBindings: function(){ + affirmUnlocked(affirmStmtOpen(this), 'clearBindings()') + capi.sqlite3_clear_bindings(this.pointer); + this._mayGet = false; + return this; + }, + /** + Resets this statement so that it may be step()ed again + from the beginning. Returns this object. Throws if this + statement has been finalized. + + If passed a truthy argument then this.clearBindings() is + also called, otherwise any existing bindings, along with + any memory allocated for them, are retained. + */ + reset: function(alsoClearBinds){ + affirmUnlocked(this,'reset()'); + if(alsoClearBinds) this.clearBindings(); + capi.sqlite3_reset(affirmStmtOpen(this).pointer); + this._mayGet = false; + return this; + }, + /** + Binds one or more values to its bindable parameters. It + accepts 1 or 2 arguments: + + If passed a single argument, it must be either an array, an + object, or a value of a bindable type (see below). + + If passed 2 arguments, the first one is the 1-based bind + index or bindable parameter name and the second one must be + a value of a bindable type. + + Bindable value types: + + - null is bound as NULL. + + - undefined as a standalone value is a no-op intended to + simplify certain client-side use cases: passing undefined as + a value to this function will not actually bind anything and + this function will skip confirmation that binding is even + legal. (Those semantics simplify certain client-side uses.) + Conversely, a value of undefined as an array or object + property when binding an array/object (see below) is treated + the same as null. + + - Numbers are bound as either doubles or integers: doubles if + they are larger than 32 bits, else double or int32, depending + on whether they have a fractional part. Booleans are bound as + integer 0 or 1. It is not expected the distinction of binding + doubles which have no fractional parts is integers is + significant for the majority of clients due to sqlite3's data + typing model. If [BigInt] support is enabled then this + routine will bind BigInt values as 64-bit integers if they'll + fit in 64 bits. If that support disabled, it will store the + BigInt as an int32 or a double if it can do so without loss + of precision. If the BigInt is _too BigInt_ then it will + throw. + + - Strings are bound as strings (use bindAsBlob() to force + blob binding). + + - Uint8Array and Int8Array instances are bound as blobs. + (TODO: binding the other TypedArray types.) + + If passed an array, each element of the array is bound at + the parameter index equal to the array index plus 1 + (because arrays are 0-based but binding is 1-based). + + If passed an object, each object key is treated as a + bindable parameter name. The object keys _must_ match any + bindable parameter names, including any `$`, `@`, or `:` + prefix. Because `$` is a legal identifier chararacter in + JavaScript, that is the suggested prefix for bindable + parameters: `stmt.bind({$a: 1, $b: 2})`. + + It returns this object on success and throws on + error. Errors include: + + - Any bind index is out of range, a named bind parameter + does not match, or this statement has no bindable + parameters. + + - Any value to bind is of an unsupported type. + + - Passed no arguments or more than two. + + - The statement has been finalized. + */ + bind: function(/*[ndx,] arg*/){ + affirmStmtOpen(this); + let ndx, arg; + switch(arguments.length){ + case 1: ndx = 1; arg = arguments[0]; break; + case 2: ndx = arguments[0]; arg = arguments[1]; break; + default: toss3("Invalid bind() arguments."); + } + if(undefined===arg){ + /* It might seem intuitive to bind undefined as NULL + but this approach simplifies certain client-side + uses when passing on arguments between 2+ levels of + functions. */ + return this; + }else if(!this.parameterCount){ + toss3("This statement has no bindable parameters."); + } + this._mayGet = false; + if(null===arg){ + /* bind NULL */ + return bindOne(this, ndx, BindTypes.null, arg); + } + else if(Array.isArray(arg)){ + /* bind each entry by index */ + if(1!==arguments.length){ + toss3("When binding an array, an index argument is not permitted."); + } + arg.forEach((v,i)=>bindOne(this, i+1, affirmSupportedBindType(v), v)); + return this; + } + else if('object'===typeof arg/*null was checked above*/ + && !util.isBindableTypedArray(arg)){ + /* Treat each property of arg as a named bound parameter. */ + if(1!==arguments.length){ + toss3("When binding an object, an index argument is not permitted."); + } + Object.keys(arg) + .forEach(k=>bindOne(this, k, + affirmSupportedBindType(arg[k]), + arg[k])); + return this; + }else{ + return bindOne(this, ndx, affirmSupportedBindType(arg), arg); + } + toss3("Should not reach this point."); + }, + /** + Special case of bind() which binds the given value using the + BLOB binding mechanism instead of the default selected one for + the value. The ndx may be a numbered or named bind index. The + value must be of type string, null/undefined (both get treated + as null), or a TypedArray of a type supported by the bind() + API. + + If passed a single argument, a bind index of 1 is assumed and + the first argument is the value. + */ + bindAsBlob: function(ndx,arg){ + affirmStmtOpen(this); + if(1===arguments.length){ + arg = ndx; + ndx = 1; + } + const t = affirmSupportedBindType(arg); + if(BindTypes.string !== t && BindTypes.blob !== t + && BindTypes.null !== t){ + toss3("Invalid value type for bindAsBlob()"); + } + bindOne(this, ndx, BindTypes.blob, arg); + this._mayGet = false; + return this; + }, + /** + Steps the statement one time. If the result indicates that a + row of data is available, a truthy value is returned. + If no row of data is available, a falsy + value is returned. Throws on error. + */ + step: function(){ + affirmUnlocked(this, 'step()'); + const rc = capi.sqlite3_step(affirmStmtOpen(this).pointer); + switch(rc){ + case capi.SQLITE_DONE: return this._mayGet = false; + case capi.SQLITE_ROW: return this._mayGet = true; + default: + this._mayGet = false; + console.warn("sqlite3_step() rc=",rc, + capi.sqlite3_js_rc_str(rc), + "SQL =", capi.sqlite3_sql(this.pointer)); + DB.checkRc(this.db.pointer, rc); + } + }, + /** + Functions exactly like step() except that... + + 1) On success, it calls this.reset() and returns this object. + 2) On error, it throws and does not call reset(). + + This is intended to simplify constructs like: + + ``` + for(...) { + stmt.bind(...).stepReset(); + } + ``` + + Note that the reset() call makes it illegal to call this.get() + after the step. + */ + stepReset: function(){ + this.step(); + return this.reset(); + }, + /** + Functions like step() except that it finalizes this statement + immediately after stepping unless the step cannot be performed + because the statement is locked. Throws on error, but any error + other than the statement-is-locked case will also trigger + finalization of this statement. + + On success, it returns true if the step indicated that a row of + data was available, else it returns false. + + This is intended to simplify use cases such as: + + ``` + aDb.prepare("insert into foo(a) values(?)").bind(123).stepFinalize(); + ``` + */ + stepFinalize: function(){ + const rc = this.step(); + this.finalize(); + return rc; + }, + /** + Fetches the value from the given 0-based column index of + the current data row, throwing if index is out of range. + + Requires that step() has just returned a truthy value, else + an exception is thrown. + + By default it will determine the data type of the result + automatically. If passed a second arugment, it must be one + of the enumeration values for sqlite3 types, which are + defined as members of the sqlite3 module: SQLITE_INTEGER, + SQLITE_FLOAT, SQLITE_TEXT, SQLITE_BLOB. Any other value, + except for undefined, will trigger an exception. Passing + undefined is the same as not passing a value. It is legal + to, e.g., fetch an integer value as a string, in which case + sqlite3 will convert the value to a string. + + If ndx is an array, this function behaves a differently: it + assigns the indexes of the array, from 0 to the number of + result columns, to the values of the corresponding column, + and returns that array. + + If ndx is a plain object, this function behaves even + differentlier: it assigns the properties of the object to + the values of their corresponding result columns. + + Blobs are returned as Uint8Array instances. + + Potential TODO: add type ID SQLITE_JSON, which fetches the + result as a string and passes it (if it's not null) to + JSON.parse(), returning the result of that. Until then, + getJSON() can be used for that. + */ + get: function(ndx,asType){ + if(!affirmStmtOpen(this)._mayGet){ + toss3("Stmt.step() has not (recently) returned true."); + } + if(Array.isArray(ndx)){ + let i = 0; + while(i<this.columnCount){ + ndx[i] = this.get(i++); + } + return ndx; + }else if(ndx && 'object'===typeof ndx){ + let i = 0; + while(i<this.columnCount){ + ndx[capi.sqlite3_column_name(this.pointer,i)] = this.get(i++); + } + return ndx; + } + affirmColIndex(this, ndx); + switch(undefined===asType + ? capi.sqlite3_column_type(this.pointer, ndx) + : asType){ + case capi.SQLITE_NULL: return null; + case capi.SQLITE_INTEGER:{ + if(wasm.bigIntEnabled){ + const rc = capi.sqlite3_column_int64(this.pointer, ndx); + if(rc>=Number.MIN_SAFE_INTEGER && rc<=Number.MAX_SAFE_INTEGER){ + /* Coerce "normal" number ranges to normal number values, + and only return BigInt-type values for numbers out of this + range. */ + return Number(rc).valueOf(); + } + return rc; + }else{ + const rc = capi.sqlite3_column_double(this.pointer, ndx); + if(rc>Number.MAX_SAFE_INTEGER || rc<Number.MIN_SAFE_INTEGER){ + /* Throwing here is arguable but, since we're explicitly + extracting an SQLITE_INTEGER-type value, it seems fair to throw + if the extracted number is out of range for that type. + This policy may be laxened to simply pass on the number and + hope for the best, as the C API would do. */ + toss3("Integer is out of range for JS integer range: "+rc); + } + //console.log("get integer rc=",rc,isInt32(rc)); + return util.isInt32(rc) ? (rc | 0) : rc; + } + } + case capi.SQLITE_FLOAT: + return capi.sqlite3_column_double(this.pointer, ndx); + case capi.SQLITE_TEXT: + return capi.sqlite3_column_text(this.pointer, ndx); + case capi.SQLITE_BLOB: { + const n = capi.sqlite3_column_bytes(this.pointer, ndx), + ptr = capi.sqlite3_column_blob(this.pointer, ndx), + rc = new Uint8Array(n); + //heap = n ? wasm.heap8() : false; + if(n) rc.set(wasm.heap8u().slice(ptr, ptr+n), 0); + //for(let i = 0; i < n; ++i) rc[i] = heap[ptr + i]; + if(n && this.db._blobXfer instanceof Array){ + /* This is an optimization soley for the + Worker-based API. These values will be + transfered to the main thread directly + instead of being copied. */ + this.db._blobXfer.push(rc.buffer); + } + return rc; + } + default: toss3("Don't know how to translate", + "type of result column #"+ndx+"."); + } + toss3("Not reached."); + }, + /** Equivalent to get(ndx) but coerces the result to an + integer. */ + getInt: function(ndx){return this.get(ndx,capi.SQLITE_INTEGER)}, + /** Equivalent to get(ndx) but coerces the result to a + float. */ + getFloat: function(ndx){return this.get(ndx,capi.SQLITE_FLOAT)}, + /** Equivalent to get(ndx) but coerces the result to a + string. */ + getString: function(ndx){return this.get(ndx,capi.SQLITE_TEXT)}, + /** Equivalent to get(ndx) but coerces the result to a + Uint8Array. */ + getBlob: function(ndx){return this.get(ndx,capi.SQLITE_BLOB)}, + /** + A convenience wrapper around get() which fetches the value + as a string and then, if it is not null, passes it to + JSON.parse(), returning that result. Throws if parsing + fails. If the result is null, null is returned. An empty + string, on the other hand, will trigger an exception. + */ + getJSON: function(ndx){ + const s = this.get(ndx, capi.SQLITE_STRING); + return null===s ? s : JSON.parse(s); + }, + // Design note: the only reason most of these getters have a 'get' + // prefix is for consistency with getVALUE_TYPE(). The latter + // arguably really need that prefix for API readability and the + // rest arguably don't, but consistency is a powerful thing. + /** + Returns the result column name of the given index, or + throws if index is out of bounds or this statement has been + finalized. This can be used without having run step() + first. + */ + getColumnName: function(ndx){ + return capi.sqlite3_column_name( + affirmColIndex(affirmStmtOpen(this),ndx).pointer, ndx + ); + }, + /** + If this statement potentially has result columns, this + function returns an array of all such names. If passed an + array, it is used as the target and all names are appended + to it. Returns the target array. Throws if this statement + cannot have result columns. This object's columnCount member + holds the number of columns. + */ + getColumnNames: function(tgt=[]){ + affirmColIndex(affirmStmtOpen(this),0); + for(let i = 0; i < this.columnCount; ++i){ + tgt.push(capi.sqlite3_column_name(this.pointer, i)); + } + return tgt; + }, + /** + If this statement has named bindable parameters and the + given name matches one, its 1-based bind index is + returned. If no match is found, 0 is returned. If it has no + bindable parameters, the undefined value is returned. + */ + getParamIndex: function(name){ + return (affirmStmtOpen(this).parameterCount + ? capi.sqlite3_bind_parameter_index(this.pointer, name) + : undefined); + } + }/*Stmt.prototype*/; + + {/* Add the `pointer` property to DB and Stmt. */ + const prop = { + enumerable: true, + get: function(){return __ptrMap.get(this)}, + set: ()=>toss3("The pointer property is read-only.") + } + Object.defineProperty(Stmt.prototype, 'pointer', prop); + Object.defineProperty(DB.prototype, 'pointer', prop); + } + + /** The OO API's public namespace. */ + sqlite3.oo1 = { + version: { + lib: capi.sqlite3_libversion(), + ooApi: "0.1" + }, + DB, + Stmt + }/*oo1 object*/; + + if(util.isUIThread()){ + /** + Functionally equivalent to DB(storageName,'c','kvvfs') except + that it throws if the given storage name is not one of 'local' + or 'session'. + */ + sqlite3.oo1.JsStorageDb = function(storageName='session'){ + if('session'!==storageName && 'local'!==storageName){ + toss3("JsStorageDb db name must be one of 'session' or 'local'."); + } + dbCtorHelper.call(this, { + filename: storageName, + flags: 'c', + vfs: "kvvfs" + }); + }; + const jdb = sqlite3.oo1.JsStorageDb; + jdb.prototype = Object.create(DB.prototype); + /** Equivalent to sqlite3_js_kvvfs_clear(). */ + jdb.clearStorage = capi.sqlite3_js_kvvfs_clear; + /** + Clears this database instance's storage or throws if this + instance has been closed. Returns the number of + database blocks which were cleaned up. + */ + jdb.prototype.clearStorage = function(){ + return jdb.clearStorage(affirmDbOpen(this).filename); + }; + /** Equivalent to sqlite3_js_kvvfs_size(). */ + jdb.storageSize = capi.sqlite3_js_kvvfs_size; + /** + Returns the _approximate_ number of bytes this database takes + up in its storage or throws if this instance has been closed. + */ + jdb.prototype.storageSize = function(){ + return jdb.storageSize(affirmDbOpen(this).filename); + }; + }/*main-window-only bits*/ + +}); + |