gecko/netwerk/protocol/http/Http2Compression.h

209 lines
6.4 KiB
C++

/* -*- 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/. */
#ifndef mozilla_net_Http2Compression_Internal_h
#define mozilla_net_Http2Compression_Internal_h
// HPACK
// tools.ietf.org/html/draft-ietf-httpbis-header-compression-04
#include "mozilla/Attributes.h"
#include "nsDeque.h"
#include "nsString.h"
namespace mozilla {
namespace net {
struct HuffmanIncomingTable;
void Http2CompressionCleanup();
class nvPair
{
public:
nvPair(const nsACString &name, const nsACString &value)
: mName(name)
, mValue(value)
{ }
uint32_t Size() const { return mName.Length() + mValue.Length() + 32; }
nsCString mName;
nsCString mValue;
};
class nvFIFO
{
public:
nvFIFO();
~nvFIFO();
void AddElement(const nsCString &name, const nsCString &value);
void AddElement(const nsCString &name);
void RemoveElement();
uint32_t ByteCount() const;
uint32_t Length() const;
uint32_t VariableLength() const;
void Clear();
const nvPair *operator[] (int32_t index) const;
private:
uint32_t mByteCount;
nsDeque mTable;
};
class Http2BaseCompressor
{
public:
Http2BaseCompressor();
virtual ~Http2BaseCompressor() { };
protected:
// this will become a HTTP/2 SETTINGS value in a future draft
const static uint32_t kDefaultMaxBuffer = 4096;
virtual void ClearHeaderTable();
virtual void UpdateReferenceSet(int32_t delta);
virtual void IncrementReferenceSetIndices();
virtual void MakeRoom(uint32_t amount) = 0;
nsAutoTArray<uint32_t, 64> mReferenceSet; // list of indicies
// the alternate set is used to track the emitted headers when
// processing input for a header set. The input to the compressor
// is a series of nvpairs, the input to the decompressor is the
// series of op codes that make up the header block.
//
// after processing the input the compressor compares the alternate
// set to the inherited reference set and generates indicies to
// toggle off any members of alternate - inherited. the alternate
// then becomes the inherited set for the next header set.
//
// after processing the input the decompressor comapres the alternate
// set to the inherited reference set and generates headers for
// anything implicit in reference - alternate.
nsAutoTArray<uint32_t, 64> mAlternateReferenceSet; // list of indicies
nsACString *mOutput;
nvFIFO mHeaderTable;
uint32_t mMaxBuffer;
};
class Http2Compressor;
class Http2Decompressor MOZ_FINAL : public Http2BaseCompressor
{
public:
Http2Decompressor() { };
virtual ~Http2Decompressor() { } ;
// NS_OK: Produces the working set of HTTP/1 formatted headers
nsresult DecodeHeaderBlock(const uint8_t *data, uint32_t datalen,
nsACString &output);
void GetStatus(nsACString &hdr) { hdr = mHeaderStatus; }
void GetHost(nsACString &hdr) { hdr = mHeaderHost; }
void GetScheme(nsACString &hdr) { hdr = mHeaderScheme; }
void GetPath(nsACString &hdr) { hdr = mHeaderPath; }
void GetMethod(nsACString &hdr) { hdr = mHeaderMethod; }
void SetCompressor(Http2Compressor *compressor) { mCompressor = compressor; }
protected:
virtual void MakeRoom(uint32_t amount) MOZ_OVERRIDE;
private:
nsresult DoIndexed();
nsresult DoLiteralWithoutIndex();
nsresult DoLiteralWithIncremental();
nsresult DoLiteralInternal(nsACString &, nsACString &, uint32_t);
nsresult DoLiteralNeverIndexed();
nsresult DoContextUpdate();
nsresult DecodeInteger(uint32_t prefixLen, uint32_t &result);
nsresult OutputHeader(uint32_t index);
nsresult OutputHeader(const nsACString &name, const nsACString &value);
nsresult CopyHeaderString(uint32_t index, nsACString &name);
nsresult CopyStringFromInput(uint32_t index, nsACString &val);
uint8_t ExtractByte(uint8_t bitsLeft, uint32_t &bytesConsumed);
nsresult CopyHuffmanStringFromInput(uint32_t index, nsACString &val);
nsresult DecodeHuffmanCharacter(HuffmanIncomingTable *table, uint8_t &c,
uint32_t &bytesConsumed, uint8_t &bitsLeft);
nsresult DecodeFinalHuffmanCharacter(HuffmanIncomingTable *table, uint8_t &c,
uint8_t &bitsLeft);
Http2Compressor *mCompressor;
nsCString mHeaderStatus;
nsCString mHeaderHost;
nsCString mHeaderScheme;
nsCString mHeaderPath;
nsCString mHeaderMethod;
// state variables when DecodeBlock() is on the stack
uint32_t mOffset;
const uint8_t *mData;
uint32_t mDataLen;
};
class Http2Compressor MOZ_FINAL : public Http2BaseCompressor
{
public:
Http2Compressor() : mParsedContentLength(-1),
mMaxBufferSetting(kDefaultMaxBuffer),
mBufferSizeChangeWaiting(false),
mLowestBufferSizeWaiting(0)
{ };
virtual ~Http2Compressor() { }
// HTTP/1 formatted header block as input - HTTP/2 formatted
// header block as output
nsresult EncodeHeaderBlock(const nsCString &nvInput,
const nsACString &method, const nsACString &path,
const nsACString &host, const nsACString &scheme,
nsACString &output);
int64_t GetParsedContentLength() { return mParsedContentLength; } // -1 on not found
void SetMaxBufferSize(uint32_t maxBufferSize);
nsresult SetMaxBufferSizeInternal(uint32_t maxBufferSize);
protected:
virtual void ClearHeaderTable() MOZ_OVERRIDE;
virtual void UpdateReferenceSet(int32_t delta) MOZ_OVERRIDE;
virtual void IncrementReferenceSetIndices() MOZ_OVERRIDE;
virtual void MakeRoom(uint32_t amount) MOZ_OVERRIDE;
private:
enum outputCode {
kNeverIndexedLiteral,
kPlainLiteral,
kIndexedLiteral,
kToggleOff,
kToggleOn,
kNop
};
void DoOutput(Http2Compressor::outputCode code,
const class nvPair *pair, uint32_t index);
void EncodeInteger(uint32_t prefixLen, uint32_t val);
void ProcessHeader(const nvPair inputPair, bool neverIndex);
void HuffmanAppend(const nsCString &value);
void EncodeTableSizeChange(uint32_t newMaxSize);
int64_t mParsedContentLength;
uint32_t mMaxBufferSetting;
bool mBufferSizeChangeWaiting;
uint32_t mLowestBufferSizeWaiting;
nsAutoTArray<uint32_t, 64> mImpliedReferenceSet;
};
} // namespace mozilla::net
} // namespace mozilla
#endif // mozilla_net_Http2Compression_Internal_h