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gecko-dev/xpcom/ds/nsPersistentProperties.cpp

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20 KiB
C++
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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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 "nsAutoPtr.h"
#define PL_ARENA_CONST_ALIGN_MASK 3
#include "nsPersistentProperties.h"
#include "nsIProperties.h"
struct PropertyTableEntry : public PLDHashEntryHdr
{
// both of these are arena-allocated
const char* mKey;
const char16_t* mValue;
};
static char16_t*
ArenaStrdup(const nsAFlatString& aString, PLArenaPool* aArena)
{
void* mem;
// add one to include the null terminator
int32_t len = (aString.Length() + 1) * sizeof(char16_t);
PL_ARENA_ALLOCATE(mem, aArena, len);
NS_ASSERTION(mem, "Couldn't allocate space!\n");
if (mem) {
memcpy(mem, aString.get(), len);
}
return static_cast<char16_t*>(mem);
}
static char*
ArenaStrdup(const nsAFlatCString& aString, PLArenaPool* aArena)
{
void* mem;
// add one to include the null terminator
int32_t len = (aString.Length() + 1) * sizeof(char);
PL_ARENA_ALLOCATE(mem, aArena, len);
NS_ASSERTION(mem, "Couldn't allocate space!\n");
if (mem) {
memcpy(mem, aString.get(), len);
}
return static_cast<char*>(mem);
}
static const struct PLDHashTableOps property_HashTableOps = {
PL_DHashAllocTable,
PL_DHashFreeTable,
PL_DHashStringKey,
PL_DHashMatchStringKey,
PL_DHashMoveEntryStub,
PL_DHashClearEntryStub,
PL_DHashFinalizeStub,
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 nsPropertiesParser
{
public:
explicit nsPropertiesParser(nsIPersistentProperties* aProps)
: mHaveMultiLine(false)
, mState(eParserState_AwaitingKey)
, 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 NS_METHOD 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;
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;
}
// no break
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;
}
NS_METHOD
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)
{
mSubclass = static_cast<nsIPersistentProperties*>(this);
PL_DHashTableInit(&mTable, &property_HashTableOps, nullptr,
sizeof(PropertyTableEntry), 16);
PL_INIT_ARENA_POOL(&mArena, "PersistentPropertyArena", 2048);
}
nsPersistentProperties::~nsPersistentProperties()
{
PL_FinishArenaPool(&mArena);
if (mTable.ops) {
PL_DHashTableFinish(&mTable);
}
}
nsresult
nsPersistentProperties::Create(nsISupports* aOuter, REFNSIID aIID,
void** aResult)
{
if (aOuter) {
return NS_ERROR_NO_AGGREGATION;
}
nsRefPtr<nsPersistentProperties> props = new nsPersistentProperties();
return props->QueryInterface(aIID, aResult);
}
NS_IMPL_ISUPPORTS(nsPersistentProperties, nsIPersistentProperties, nsIProperties)
NS_IMETHODIMP
nsPersistentProperties::Load(nsIInputStream* aIn)
{
nsresult rv = nsSimpleUnicharStreamFactory::GetInstance()->
CreateInstanceFromUTF8Stream(aIn, getter_AddRefs(mIn));
if (rv != NS_OK) {
NS_WARNING("Error creating UnicharInputStream");
return NS_ERROR_FAILURE;
}
nsPropertiesParser parser(mSubclass);
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 nsAFlatCString& flatKey = PromiseFlatCString(aKey);
PropertyTableEntry* entry = static_cast<PropertyTableEntry*>(
PL_DHashTableOperate(&mTable, flatKey.get(), PL_DHASH_ADD));
if (entry->mKey) {
aOldValue = entry->mValue;
NS_WARNING(nsPrintfCString("the property %s already exists\n",
flatKey.get()).get());
} else {
aOldValue.Truncate();
}
entry->mKey = ArenaStrdup(flatKey, &mArena);
entry->mValue = ArenaStrdup(PromiseFlatString(aNewValue), &mArena);
return NS_OK;
}
NS_IMETHODIMP
nsPersistentProperties::Save(nsIOutputStream* aOut, const nsACString& aHeader)
{
return NS_ERROR_NOT_IMPLEMENTED;
}
NS_IMETHODIMP
nsPersistentProperties::Subclass(nsIPersistentProperties* aSubclass)
{
if (aSubclass) {
mSubclass = aSubclass;
}
return NS_OK;
}
NS_IMETHODIMP
nsPersistentProperties::GetStringProperty(const nsACString& aKey,
nsAString& aValue)
{
const nsAFlatCString& flatKey = PromiseFlatCString(aKey);
PropertyTableEntry* entry = static_cast<PropertyTableEntry*>(
PL_DHashTableOperate(&mTable, flatKey.get(), PL_DHASH_LOOKUP));
if (PL_DHASH_ENTRY_IS_FREE(entry)) {
return NS_ERROR_FAILURE;
}
aValue = entry->mValue;
return NS_OK;
}
static PLDHashOperator
AddElemToArray(PLDHashTable* aTable, PLDHashEntryHdr* aHdr,
uint32_t aIndex, void* aArg)
{
nsCOMArray<nsIPropertyElement>* props =
static_cast<nsCOMArray<nsIPropertyElement>*>(aArg);
PropertyTableEntry* entry =
static_cast<PropertyTableEntry*>(aHdr);
nsPropertyElement* element =
new nsPropertyElement(nsDependentCString(entry->mKey),
nsDependentString(entry->mValue));
props->AppendObject(element);
return PL_DHASH_NEXT;
}
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
uint32_t n = PL_DHashTableEnumerate(&mTable, AddElemToArray, (void*)&props);
if (n < mTable.entryCount) {
return NS_ERROR_OUT_OF_MEMORY;
}
return NS_NewArrayEnumerator(aResult, props);
}
////////////////////////////////////////////////////////////////////////////////
// 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)
{
PropertyTableEntry* entry = static_cast<PropertyTableEntry*>(
PL_DHashTableOperate(&mTable, aProp, PL_DHASH_LOOKUP));
*aResult = (entry && PL_DHASH_ENTRY_IS_BUSY(entry));
return NS_OK;
}
NS_IMETHODIMP
nsPersistentProperties::GetKeys(uint32_t* aCount, char*** aKeys)
{
return NS_ERROR_NOT_IMPLEMENTED;
}
////////////////////////////////////////////////////////////////////////////////
// PropertyElement
////////////////////////////////////////////////////////////////////////////////
NS_METHOD
nsPropertyElement::Create(nsISupports* aOuter, REFNSIID aIID, void** aResult)
{
if (aOuter) {
return NS_ERROR_NO_AGGREGATION;
}
nsRefPtr<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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