gecko-dev/dom/indexedDB/Key.h

281 строка
8.9 KiB
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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/. */
#ifndef mozilla_dom_indexeddb_key_h__
#define mozilla_dom_indexeddb_key_h__
#include "mozilla/dom/indexedDB/IDBResult.h"
class mozIStorageStatement;
class mozIStorageValueArray;
namespace IPC {
template <typename>
struct ParamTraits;
} // namespace IPC
namespace mozilla::dom::indexedDB {
class Key {
friend struct IPC::ParamTraits<Key>;
nsCString mBuffer;
public:
enum {
eTerminator = 0,
eFloat = 0x10,
eDate = 0x20,
eString = 0x30,
eBinary = 0x40,
eArray = 0x50,
eMaxType = eArray
};
static const uint8_t kMaxArrayCollapse = uint8_t(3);
static const uint8_t kMaxRecursionDepth = uint8_t(64);
Key() { Unset(); }
explicit Key(nsCString aBuffer) : mBuffer(std::move(aBuffer)) {}
bool operator==(const Key& aOther) const {
MOZ_ASSERT(!mBuffer.IsVoid());
MOZ_ASSERT(!aOther.mBuffer.IsVoid());
return mBuffer.Equals(aOther.mBuffer);
}
bool operator!=(const Key& aOther) const {
MOZ_ASSERT(!mBuffer.IsVoid());
MOZ_ASSERT(!aOther.mBuffer.IsVoid());
return !mBuffer.Equals(aOther.mBuffer);
}
bool operator<(const Key& aOther) const {
MOZ_ASSERT(!mBuffer.IsVoid());
MOZ_ASSERT(!aOther.mBuffer.IsVoid());
return Compare(mBuffer, aOther.mBuffer) < 0;
}
bool operator>(const Key& aOther) const {
MOZ_ASSERT(!mBuffer.IsVoid());
MOZ_ASSERT(!aOther.mBuffer.IsVoid());
return Compare(mBuffer, aOther.mBuffer) > 0;
}
bool operator<=(const Key& aOther) const {
MOZ_ASSERT(!mBuffer.IsVoid());
MOZ_ASSERT(!aOther.mBuffer.IsVoid());
return Compare(mBuffer, aOther.mBuffer) <= 0;
}
bool operator>=(const Key& aOther) const {
MOZ_ASSERT(!mBuffer.IsVoid());
MOZ_ASSERT(!aOther.mBuffer.IsVoid());
return Compare(mBuffer, aOther.mBuffer) >= 0;
}
void Unset() { mBuffer.SetIsVoid(true); }
bool IsUnset() const { return mBuffer.IsVoid(); }
bool IsFloat() const { return !IsUnset() && *BufferStart() == eFloat; }
bool IsDate() const { return !IsUnset() && *BufferStart() == eDate; }
bool IsString() const { return !IsUnset() && *BufferStart() == eString; }
bool IsBinary() const { return !IsUnset() && *BufferStart() == eBinary; }
bool IsArray() const { return !IsUnset() && *BufferStart() >= eArray; }
double ToFloat() const {
MOZ_ASSERT(IsFloat());
const EncodedDataType* pos = BufferStart();
double res = DecodeNumber(pos, BufferEnd());
MOZ_ASSERT(pos >= BufferEnd());
return res;
}
double ToDateMsec() const {
MOZ_ASSERT(IsDate());
const EncodedDataType* pos = BufferStart();
double res = DecodeNumber(pos, BufferEnd());
MOZ_ASSERT(pos >= BufferEnd());
return res;
}
nsAutoString ToString() const {
MOZ_ASSERT(IsString());
const EncodedDataType* pos = BufferStart();
auto res = DecodeString(pos, BufferEnd());
MOZ_ASSERT(pos >= BufferEnd());
return res;
}
Result<Ok, nsresult> SetFromString(const nsAString& aString);
Result<Ok, nsresult> SetFromInteger(int64_t aInt) {
mBuffer.Truncate();
auto ret = EncodeNumber(double(aInt), eFloat);
TrimBuffer();
return ret;
}
// This function implements the standard algorithm "convert a value to a key".
// A key return value is indicated by returning `true` whereas `false` means
// either invalid (if `aRv.Failed()` is `false`) or an exception (otherwise).
IDBResult<Ok, IDBSpecialValue::Invalid> SetFromJSVal(
JSContext* aCx, JS::Handle<JS::Value> aVal);
nsresult ToJSVal(JSContext* aCx, JS::MutableHandle<JS::Value> aVal) const;
nsresult ToJSVal(JSContext* aCx, JS::Heap<JS::Value>& aVal) const;
// See SetFromJSVal() for the meaning of values returned by this function.
IDBResult<Ok, IDBSpecialValue::Invalid> AppendItem(
JSContext* aCx, bool aFirstOfArray, JS::Handle<JS::Value> aVal);
Result<Key, nsresult> ToLocaleAwareKey(const nsCString& aLocale) const;
void FinishArray() { TrimBuffer(); }
const nsCString& GetBuffer() const { return mBuffer; }
nsresult BindToStatement(mozIStorageStatement* aStatement,
const nsACString& aParamName) const;
nsresult SetFromStatement(mozIStorageStatement* aStatement, uint32_t aIndex);
nsresult SetFromValueArray(mozIStorageValueArray* aValues, uint32_t aIndex);
static int16_t CompareKeys(const Key& aFirst, const Key& aSecond) {
int32_t result = Compare(aFirst.mBuffer, aSecond.mBuffer);
if (result < 0) {
return -1;
}
if (result > 0) {
return 1;
}
return 0;
}
private:
class MOZ_STACK_CLASS ArrayValueEncoder;
using EncodedDataType = unsigned char;
const EncodedDataType* BufferStart() const {
// TODO it would be nicer if mBuffer was also using EncodedDataType
return reinterpret_cast<const EncodedDataType*>(mBuffer.BeginReading());
}
const EncodedDataType* BufferEnd() const {
return reinterpret_cast<const EncodedDataType*>(mBuffer.EndReading());
}
// Encoding helper. Trims trailing zeros off of mBuffer as a post-processing
// step.
void TrimBuffer() {
const char* end = mBuffer.EndReading() - 1;
while (!*end) {
--end;
}
mBuffer.Truncate(end + 1 - mBuffer.BeginReading());
}
// Encoding functions. These append the encoded value to the end of mBuffer
IDBResult<Ok, IDBSpecialValue::Invalid> EncodeJSVal(
JSContext* aCx, JS::Handle<JS::Value> aVal, uint8_t aTypeOffset);
Result<Ok, nsresult> EncodeString(const nsAString& aString,
uint8_t aTypeOffset);
template <typename T>
Result<Ok, nsresult> EncodeString(Span<const T> aInput, uint8_t aTypeOffset);
template <typename T>
Result<Ok, nsresult> EncodeAsString(Span<const T> aInput, uint8_t aType);
Result<Ok, nsresult> EncodeLocaleString(const nsAString& aString,
uint8_t aTypeOffset,
const nsCString& aLocale);
Result<Ok, nsresult> EncodeNumber(double aFloat, uint8_t aType);
Result<Ok, nsresult> EncodeBinary(JSObject* aObject, bool aIsViewObject,
uint8_t aTypeOffset);
// Decoding functions. aPos points into mBuffer and is adjusted to point
// past the consumed value. (Note: this may be beyond aEnd).
static nsresult DecodeJSVal(const EncodedDataType*& aPos,
const EncodedDataType* aEnd, JSContext* aCx,
JS::MutableHandle<JS::Value> aVal);
static nsAutoString DecodeString(const EncodedDataType*& aPos,
const EncodedDataType* aEnd);
static double DecodeNumber(const EncodedDataType*& aPos,
const EncodedDataType* aEnd);
static JSObject* DecodeBinary(const EncodedDataType*& aPos,
const EncodedDataType* aEnd, JSContext* aCx);
// Returns the size of the decoded data for stringy (string or binary),
// excluding a null terminator.
// On return, aOutSectionEnd points to the last byte behind the current
// encoded section, i.e. either aEnd, or the eTerminator.
// T is the base type for the decoded data.
template <typename T>
static uint32_t CalcDecodedStringySize(
const EncodedDataType* aBegin, const EncodedDataType* aEnd,
const EncodedDataType** aOutEncodedSectionEnd);
static uint32_t LengthOfEncodedBinary(const EncodedDataType* aPos,
const EncodedDataType* aEnd);
template <typename T>
static void DecodeAsStringy(const EncodedDataType* aEncodedSectionBegin,
const EncodedDataType* aEncodedSectionEnd,
uint32_t aDecodedLength, T* aOut);
template <EncodedDataType TypeMask, typename T, typename AcquireBuffer,
typename AcquireEmpty>
static void DecodeStringy(const EncodedDataType*& aPos,
const EncodedDataType* aEnd,
const AcquireBuffer& acquireBuffer,
const AcquireEmpty& acquireEmpty);
IDBResult<Ok, IDBSpecialValue::Invalid> EncodeJSValInternal(
JSContext* aCx, JS::Handle<JS::Value> aVal, uint8_t aTypeOffset,
uint16_t aRecursionDepth);
static nsresult DecodeJSValInternal(const EncodedDataType*& aPos,
const EncodedDataType* aEnd,
JSContext* aCx, uint8_t aTypeOffset,
JS::MutableHandle<JS::Value> aVal,
uint16_t aRecursionDepth);
template <typename T>
nsresult SetFromSource(T* aSource, uint32_t aIndex);
};
} // namespace mozilla::dom::indexedDB
#endif // mozilla_dom_indexeddb_key_h__