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Diffstat (limited to 'xpcom/ds/nsPersistentProperties.cpp')
| -rw-r--r-- | xpcom/ds/nsPersistentProperties.cpp | 583 |
1 files changed, 583 insertions, 0 deletions
diff --git a/xpcom/ds/nsPersistentProperties.cpp b/xpcom/ds/nsPersistentProperties.cpp new file mode 100644 index 0000000000..51a4891e19 --- /dev/null +++ b/xpcom/ds/nsPersistentProperties.cpp @@ -0,0 +1,583 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "nsArrayEnumerator.h" +#include "nsID.h" +#include "nsCOMArray.h" +#include "nsUnicharInputStream.h" +#include "nsPrintfCString.h" + +#include "nsPersistentProperties.h" +#include "nsIProperties.h" + +#include "mozilla/ArenaAllocatorExtensions.h" + +using mozilla::ArenaStrdup; + +struct PropertyTableEntry : public PLDHashEntryHdr { + // both of these are arena-allocated + const char* mKey; + const char16_t* mValue; +}; + +static const struct PLDHashTableOps property_HashTableOps = { + PLDHashTable::HashStringKey, + PLDHashTable::MatchStringKey, + PLDHashTable::MoveEntryStub, + PLDHashTable::ClearEntryStub, + nullptr, +}; + +// +// parser stuff +// +enum EParserState { + eParserState_AwaitingKey, + eParserState_Key, + eParserState_AwaitingValue, + eParserState_Value, + eParserState_Comment +}; + +enum EParserSpecial { + eParserSpecial_None, // not parsing a special character + eParserSpecial_Escaped, // awaiting a special character + eParserSpecial_Unicode // parsing a \Uxxx value +}; + +class MOZ_STACK_CLASS nsPropertiesParser { + public: + explicit nsPropertiesParser(nsIPersistentProperties* aProps) + : mUnicodeValuesRead(0), + mUnicodeValue(u'\0'), + mHaveMultiLine(false), + mMultiLineCanSkipN(false), + mMinLength(0), + mState(eParserState_AwaitingKey), + mSpecialState(eParserSpecial_None), + mProps(aProps) {} + + void FinishValueState(nsAString& aOldValue) { + static const char trimThese[] = " \t"; + mKey.Trim(trimThese, false, true); + + // This is really ugly hack but it should be fast + char16_t backup_char; + uint32_t minLength = mMinLength; + if (minLength) { + backup_char = mValue[minLength - 1]; + mValue.SetCharAt('x', minLength - 1); + } + mValue.Trim(trimThese, false, true); + if (minLength) { + mValue.SetCharAt(backup_char, minLength - 1); + } + + mProps->SetStringProperty(NS_ConvertUTF16toUTF8(mKey), mValue, aOldValue); + mSpecialState = eParserSpecial_None; + WaitForKey(); + } + + EParserState GetState() { return mState; } + + static nsresult SegmentWriter(nsIUnicharInputStream* aStream, void* aClosure, + const char16_t* aFromSegment, + uint32_t aToOffset, uint32_t aCount, + uint32_t* aWriteCount); + + nsresult ParseBuffer(const char16_t* aBuffer, uint32_t aBufferLength); + + private: + bool ParseValueCharacter( + char16_t aChar, // character that is just being parsed + const char16_t* aCur, // pointer to character aChar in the buffer + const char16_t*& aTokenStart, // string copying is done in blocks as big + // as possible, aTokenStart points to the + // beginning of this block + nsAString& aOldValue); // when duplicate property is found, new value + // is stored into hashtable and the old one is + // placed in this variable + + void WaitForKey() { mState = eParserState_AwaitingKey; } + + void EnterKeyState() { + mKey.Truncate(); + mState = eParserState_Key; + } + + void WaitForValue() { mState = eParserState_AwaitingValue; } + + void EnterValueState() { + mValue.Truncate(); + mMinLength = 0; + mState = eParserState_Value; + mSpecialState = eParserSpecial_None; + } + + void EnterCommentState() { mState = eParserState_Comment; } + + nsAutoString mKey; + nsAutoString mValue; + + uint32_t mUnicodeValuesRead; // should be 4! + char16_t mUnicodeValue; // currently parsed unicode value + bool mHaveMultiLine; // is TRUE when last processed characters form + // any of following sequences: + // - "\\\r" + // - "\\\n" + // - "\\\r\n" + // - any sequence above followed by any + // combination of ' ' and '\t' + bool mMultiLineCanSkipN; // TRUE if "\\\r" was detected + uint32_t mMinLength; // limit right trimming at the end to not trim + // escaped whitespaces + EParserState mState; + // if we see a '\' then we enter this special state + EParserSpecial mSpecialState; + nsCOMPtr<nsIPersistentProperties> mProps; +}; + +inline bool IsWhiteSpace(char16_t aChar) { + return (aChar == ' ') || (aChar == '\t') || (aChar == '\r') || + (aChar == '\n'); +} + +inline bool IsEOL(char16_t aChar) { return (aChar == '\r') || (aChar == '\n'); } + +bool nsPropertiesParser::ParseValueCharacter(char16_t aChar, + const char16_t* aCur, + const char16_t*& aTokenStart, + nsAString& aOldValue) { + switch (mSpecialState) { + // the normal state - look for special characters + case eParserSpecial_None: + switch (aChar) { + case '\\': + if (mHaveMultiLine) { + // there is nothing to append to mValue yet + mHaveMultiLine = false; + } else { + mValue += Substring(aTokenStart, aCur); + } + + mSpecialState = eParserSpecial_Escaped; + break; + + case '\n': + // if we detected multiline and got only "\\\r" ignore next "\n" if + // any + if (mHaveMultiLine && mMultiLineCanSkipN) { + // but don't allow another '\n' to be skipped + mMultiLineCanSkipN = false; + // Now there is nothing to append to the mValue since we are + // skipping whitespaces at the beginning of the new line of the + // multiline property. Set aTokenStart properly to ensure that + // nothing is appended if we find regular line-end or the end of the + // buffer. + aTokenStart = aCur + 1; + break; + } + [[fallthrough]]; + + case '\r': + // we're done! We have a key and value + mValue += Substring(aTokenStart, aCur); + FinishValueState(aOldValue); + mHaveMultiLine = false; + break; + + default: + // there is nothing to do with normal characters, + // but handle multilines correctly + if (mHaveMultiLine) { + if (aChar == ' ' || aChar == '\t') { + // don't allow another '\n' to be skipped + mMultiLineCanSkipN = false; + // Now there is nothing to append to the mValue since we are + // skipping whitespaces at the beginning of the new line of the + // multiline property. Set aTokenStart properly to ensure that + // nothing is appended if we find regular line-end or the end of + // the buffer. + aTokenStart = aCur + 1; + break; + } + mHaveMultiLine = false; + aTokenStart = aCur; + } + break; // from switch on (aChar) + } + break; // from switch on (mSpecialState) + + // saw a \ character, so parse the character after that + case eParserSpecial_Escaped: + // probably want to start parsing at the next token + // other characters, like 'u' might override this + aTokenStart = aCur + 1; + mSpecialState = eParserSpecial_None; + + switch (aChar) { + // the easy characters - \t, \n, and so forth + case 't': + mValue += char16_t('\t'); + mMinLength = mValue.Length(); + break; + case 'n': + mValue += char16_t('\n'); + mMinLength = mValue.Length(); + break; + case 'r': + mValue += char16_t('\r'); + mMinLength = mValue.Length(); + break; + case '\\': + mValue += char16_t('\\'); + break; + + // switch to unicode mode! + case 'u': + case 'U': + mSpecialState = eParserSpecial_Unicode; + mUnicodeValuesRead = 0; + mUnicodeValue = 0; + break; + + // a \ immediately followed by a newline means we're going multiline + case '\r': + case '\n': + mHaveMultiLine = true; + mMultiLineCanSkipN = (aChar == '\r'); + mSpecialState = eParserSpecial_None; + break; + + default: + // don't recognize the character, so just append it + mValue += aChar; + break; + } + break; + + // we're in the middle of parsing a 4-character unicode value + // like \u5f39 + case eParserSpecial_Unicode: + if ('0' <= aChar && aChar <= '9') { + mUnicodeValue = (mUnicodeValue << 4) | (aChar - '0'); + } else if ('a' <= aChar && aChar <= 'f') { + mUnicodeValue = (mUnicodeValue << 4) | (aChar - 'a' + 0x0a); + } else if ('A' <= aChar && aChar <= 'F') { + mUnicodeValue = (mUnicodeValue << 4) | (aChar - 'A' + 0x0a); + } else { + // non-hex character. Append what we have, and move on. + mValue += mUnicodeValue; + mMinLength = mValue.Length(); + mSpecialState = eParserSpecial_None; + + // leave aTokenStart at this unknown character, so it gets appended + aTokenStart = aCur; + + // ensure parsing this non-hex character again + return false; + } + + if (++mUnicodeValuesRead >= 4) { + aTokenStart = aCur + 1; + mSpecialState = eParserSpecial_None; + mValue += mUnicodeValue; + mMinLength = mValue.Length(); + } + + break; + } + + return true; +} + +nsresult nsPropertiesParser::SegmentWriter(nsIUnicharInputStream* aStream, + void* aClosure, + const char16_t* aFromSegment, + uint32_t aToOffset, uint32_t aCount, + uint32_t* aWriteCount) { + nsPropertiesParser* parser = static_cast<nsPropertiesParser*>(aClosure); + parser->ParseBuffer(aFromSegment, aCount); + + *aWriteCount = aCount; + return NS_OK; +} + +nsresult nsPropertiesParser::ParseBuffer(const char16_t* aBuffer, + uint32_t aBufferLength) { + const char16_t* cur = aBuffer; + const char16_t* end = aBuffer + aBufferLength; + + // points to the start/end of the current key or value + const char16_t* tokenStart = nullptr; + + // if we're in the middle of parsing a key or value, make sure + // the current token points to the beginning of the current buffer + if (mState == eParserState_Key || mState == eParserState_Value) { + tokenStart = aBuffer; + } + + nsAutoString oldValue; + + while (cur != end) { + char16_t c = *cur; + + switch (mState) { + case eParserState_AwaitingKey: + if (c == '#' || c == '!') { + EnterCommentState(); + } + + else if (!IsWhiteSpace(c)) { + // not a comment, not whitespace, we must have found a key! + EnterKeyState(); + tokenStart = cur; + } + break; + + case eParserState_Key: + if (c == '=' || c == ':') { + mKey += Substring(tokenStart, cur); + WaitForValue(); + } + break; + + case eParserState_AwaitingValue: + if (IsEOL(c)) { + // no value at all! mimic the normal value-ending + EnterValueState(); + FinishValueState(oldValue); + } + + // ignore white space leading up to the value + else if (!IsWhiteSpace(c)) { + tokenStart = cur; + EnterValueState(); + + // make sure to handle this first character + if (ParseValueCharacter(c, cur, tokenStart, oldValue)) { + cur++; + } + // If the character isn't consumed, don't do cur++ and parse + // the character again. This can happen f.e. for char 'X' in sequence + // "\u00X". This character can be control character and must be + // processed again. + continue; + } + break; + + case eParserState_Value: + if (ParseValueCharacter(c, cur, tokenStart, oldValue)) { + cur++; + } + // See few lines above for reason of doing this + continue; + + case eParserState_Comment: + // stay in this state till we hit EOL + if (c == '\r' || c == '\n') { + WaitForKey(); + } + break; + } + + // finally, advance to the next character + cur++; + } + + // if we're still parsing the value and are in eParserSpecial_None, then + // append whatever we have.. + if (mState == eParserState_Value && tokenStart && + mSpecialState == eParserSpecial_None) { + mValue += Substring(tokenStart, cur); + } + // if we're still parsing the key, then append whatever we have.. + else if (mState == eParserState_Key && tokenStart) { + mKey += Substring(tokenStart, cur); + } + + return NS_OK; +} + +nsPersistentProperties::nsPersistentProperties() + : mIn(nullptr), + mTable(&property_HashTableOps, sizeof(PropertyTableEntry), 16) {} + +nsPersistentProperties::~nsPersistentProperties() = default; + +size_t nsPersistentProperties::SizeOfIncludingThis( + mozilla::MallocSizeOf aMallocSizeOf) { + // The memory used by mTable is accounted for in mArena. + size_t n = 0; + n += mArena.SizeOfExcludingThis(aMallocSizeOf); + n += mTable.ShallowSizeOfExcludingThis(aMallocSizeOf); + return aMallocSizeOf(this) + n; +} + +NS_IMPL_ISUPPORTS(nsPersistentProperties, nsIPersistentProperties, + nsIProperties) + +NS_IMETHODIMP +nsPersistentProperties::Load(nsIInputStream* aIn) { + nsresult rv = NS_NewUnicharInputStream(aIn, getter_AddRefs(mIn)); + + if (rv != NS_OK) { + NS_WARNING("Error creating UnicharInputStream"); + return NS_ERROR_FAILURE; + } + + nsPropertiesParser parser(this); + + uint32_t nProcessed; + // If this 4096 is changed to some other value, make sure to adjust + // the bug121341.properties test file accordingly. + while (NS_SUCCEEDED(rv = mIn->ReadSegments(nsPropertiesParser::SegmentWriter, + &parser, 4096, &nProcessed)) && + nProcessed != 0) + ; + mIn = nullptr; + if (NS_FAILED(rv)) { + return rv; + } + + // We may have an unprocessed value at this point + // if the last line did not have a proper line ending. + if (parser.GetState() == eParserState_Value) { + nsAutoString oldValue; + parser.FinishValueState(oldValue); + } + + return NS_OK; +} + +NS_IMETHODIMP +nsPersistentProperties::SetStringProperty(const nsACString& aKey, + const nsAString& aNewValue, + nsAString& aOldValue) { + const nsCString& flatKey = PromiseFlatCString(aKey); + auto entry = static_cast<PropertyTableEntry*>(mTable.Add(flatKey.get())); + + if (entry->mKey) { + aOldValue = entry->mValue; + NS_WARNING( + nsPrintfCString("the property %s already exists", flatKey.get()).get()); + } else { + aOldValue.Truncate(); + } + + entry->mKey = ArenaStrdup(flatKey, mArena); + entry->mValue = ArenaStrdup(aNewValue, mArena); + + return NS_OK; +} + +NS_IMETHODIMP +nsPersistentProperties::Save(nsIOutputStream* aOut, const nsACString& aHeader) { + return NS_ERROR_NOT_IMPLEMENTED; +} + +NS_IMETHODIMP +nsPersistentProperties::GetStringProperty(const nsACString& aKey, + nsAString& aValue) { + const nsCString& flatKey = PromiseFlatCString(aKey); + + auto entry = static_cast<PropertyTableEntry*>(mTable.Search(flatKey.get())); + if (!entry) { + return NS_ERROR_FAILURE; + } + + aValue = entry->mValue; + return NS_OK; +} + +NS_IMETHODIMP +nsPersistentProperties::Enumerate(nsISimpleEnumerator** aResult) { + nsCOMArray<nsIPropertyElement> props; + + // We know the necessary size; we can avoid growing it while adding elements + props.SetCapacity(mTable.EntryCount()); + + // Step through hash entries populating a transient array + for (auto iter = mTable.Iter(); !iter.Done(); iter.Next()) { + auto entry = static_cast<PropertyTableEntry*>(iter.Get()); + + RefPtr<nsPropertyElement> element = new nsPropertyElement( + nsDependentCString(entry->mKey), nsDependentString(entry->mValue)); + + if (!props.AppendObject(element)) { + return NS_ERROR_OUT_OF_MEMORY; + } + } + + return NS_NewArrayEnumerator(aResult, props, NS_GET_IID(nsIPropertyElement)); +} + +//////////////////////////////////////////////////////////////////////////////// +// XXX Some day we'll unify the nsIPersistentProperties interface with +// nsIProperties, but until now... + +NS_IMETHODIMP +nsPersistentProperties::Get(const char* aProp, const nsIID& aUUID, + void** aResult) { + return NS_ERROR_NOT_IMPLEMENTED; +} + +NS_IMETHODIMP +nsPersistentProperties::Set(const char* aProp, nsISupports* value) { + return NS_ERROR_NOT_IMPLEMENTED; +} +NS_IMETHODIMP +nsPersistentProperties::Undefine(const char* aProp) { + return NS_ERROR_NOT_IMPLEMENTED; +} + +NS_IMETHODIMP +nsPersistentProperties::Has(const char* aProp, bool* aResult) { + *aResult = !!mTable.Search(aProp); + return NS_OK; +} + +NS_IMETHODIMP +nsPersistentProperties::GetKeys(nsTArray<nsCString>& aKeys) { + return NS_ERROR_NOT_IMPLEMENTED; +} + +//////////////////////////////////////////////////////////////////////////////// +// PropertyElement +//////////////////////////////////////////////////////////////////////////////// + +nsresult nsPropertyElement::Create(REFNSIID aIID, void** aResult) { + RefPtr<nsPropertyElement> propElem = new nsPropertyElement(); + return propElem->QueryInterface(aIID, aResult); +} + +NS_IMPL_ISUPPORTS(nsPropertyElement, nsIPropertyElement) + +NS_IMETHODIMP +nsPropertyElement::GetKey(nsACString& aReturnKey) { + aReturnKey = mKey; + return NS_OK; +} + +NS_IMETHODIMP +nsPropertyElement::GetValue(nsAString& aReturnValue) { + aReturnValue = mValue; + return NS_OK; +} + +NS_IMETHODIMP +nsPropertyElement::SetKey(const nsACString& aKey) { + mKey = aKey; + return NS_OK; +} + +NS_IMETHODIMP +nsPropertyElement::SetValue(const nsAString& aValue) { + mValue = aValue; + return NS_OK; +} + +//////////////////////////////////////////////////////////////////////////////// |