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-rw-r--r--xpcom/ds/nsPersistentProperties.cpp584
1 files changed, 584 insertions, 0 deletions
diff --git a/xpcom/ds/nsPersistentProperties.cpp b/xpcom/ds/nsPersistentProperties.cpp
new file mode 100644
index 0000000000..4e83870742
--- /dev/null
+++ b/xpcom/ds/nsPersistentProperties.cpp
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+/* -*- 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),
+ mArena() {}
+
+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;
+}
+
+////////////////////////////////////////////////////////////////////////////////
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