michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #ifndef mozilla_net_Http2Compression_Internal_h
michael@0: #define mozilla_net_Http2Compression_Internal_h
michael@0: 
michael@0: // HPACK
michael@0: // tools.ietf.org/html/draft-ietf-httpbis-header-compression-04
michael@0: 
michael@0: #include "mozilla/Attributes.h"
michael@0: #include "nsDeque.h"
michael@0: #include "nsString.h"
michael@0: 
michael@0: namespace mozilla {
michael@0: namespace net {
michael@0: 
michael@0: struct HuffmanIncomingTable;
michael@0: 
michael@0: void Http2CompressionCleanup();
michael@0: 
michael@0: class nvPair
michael@0: {
michael@0: public:
michael@0: nvPair(const nsACString &name, const nsACString &value)
michael@0:   : mName(name)
michael@0:   , mValue(value)
michael@0:   { }
michael@0: 
michael@0:   uint32_t Size() const { return mName.Length() + mValue.Length() + 32; }
michael@0: 
michael@0:   nsCString mName;
michael@0:   nsCString mValue;
michael@0: };
michael@0: 
michael@0: class nvFIFO
michael@0: {
michael@0: public:
michael@0:   nvFIFO();
michael@0:   ~nvFIFO();
michael@0:   void AddElement(const nsCString &name, const nsCString &value);
michael@0:   void AddElement(const nsCString &name);
michael@0:   void RemoveElement();
michael@0:   uint32_t ByteCount() const;
michael@0:   uint32_t Length() const;
michael@0:   uint32_t VariableLength() const;
michael@0:   void Clear();
michael@0:   const nvPair *operator[] (int32_t index) const;
michael@0: 
michael@0: private:
michael@0:   uint32_t mByteCount;
michael@0:   nsDeque  mTable;
michael@0: };
michael@0: 
michael@0: class Http2BaseCompressor
michael@0: {
michael@0: public:
michael@0:   Http2BaseCompressor();
michael@0:   virtual ~Http2BaseCompressor() { };
michael@0: 
michael@0: protected:
michael@0:   // this will become a HTTP/2 SETTINGS value in a future draft
michael@0:   const static uint32_t kDefaultMaxBuffer = 4096;
michael@0: 
michael@0:   virtual void ClearHeaderTable();
michael@0:   virtual void UpdateReferenceSet(int32_t delta);
michael@0:   virtual void IncrementReferenceSetIndices();
michael@0:   virtual void MakeRoom(uint32_t amount) = 0;
michael@0: 
michael@0:   nsAutoTArray<uint32_t, 64> mReferenceSet; // list of indicies
michael@0: 
michael@0:   // the alternate set is used to track the emitted headers when
michael@0:   // processing input for a header set. The input to the compressor
michael@0:   // is a series of nvpairs, the input to the decompressor is the
michael@0:   // series of op codes that make up the header block.
michael@0:   //
michael@0:   // after processing the input the compressor compares the alternate
michael@0:   // set to the inherited reference set and generates indicies to
michael@0:   // toggle off any members of alternate - inherited. the alternate
michael@0:   // then becomes the inherited set for the next header set.
michael@0:   //
michael@0:   // after processing the input the decompressor comapres the alternate
michael@0:   // set to the inherited reference set and generates headers for
michael@0:   // anything implicit in reference - alternate.
michael@0:   nsAutoTArray<uint32_t, 64> mAlternateReferenceSet; // list of indicies
michael@0: 
michael@0:   nsACString *mOutput;
michael@0:   nvFIFO mHeaderTable;
michael@0: 
michael@0:   uint32_t mMaxBuffer;
michael@0: };
michael@0: 
michael@0: class Http2Compressor;
michael@0: 
michael@0: class Http2Decompressor MOZ_FINAL : public Http2BaseCompressor
michael@0: {
michael@0: public:
michael@0:   Http2Decompressor() { };
michael@0:   virtual ~Http2Decompressor() { } ;
michael@0: 
michael@0:   // NS_OK: Produces the working set of HTTP/1 formatted headers
michael@0:   nsresult DecodeHeaderBlock(const uint8_t *data, uint32_t datalen,
michael@0:                              nsACString &output);
michael@0: 
michael@0:   void GetStatus(nsACString &hdr) { hdr = mHeaderStatus; }
michael@0:   void GetHost(nsACString &hdr) { hdr = mHeaderHost; }
michael@0:   void GetScheme(nsACString &hdr) { hdr = mHeaderScheme; }
michael@0:   void GetPath(nsACString &hdr) { hdr = mHeaderPath; }
michael@0:   void GetMethod(nsACString &hdr) { hdr = mHeaderMethod; }
michael@0:   void SetCompressor(Http2Compressor *compressor) { mCompressor = compressor; }
michael@0: 
michael@0: protected:
michael@0:   virtual void MakeRoom(uint32_t amount) MOZ_OVERRIDE;
michael@0: 
michael@0: private:
michael@0:   nsresult DoIndexed();
michael@0:   nsresult DoLiteralWithoutIndex();
michael@0:   nsresult DoLiteralWithIncremental();
michael@0:   nsresult DoLiteralInternal(nsACString &, nsACString &);
michael@0: 
michael@0:   nsresult DecodeInteger(uint32_t prefixLen, uint32_t &result);
michael@0:   nsresult OutputHeader(uint32_t index);
michael@0:   nsresult OutputHeader(const nsACString &name, const nsACString &value);
michael@0: 
michael@0:   nsresult CopyHeaderString(uint32_t index, nsACString &name);
michael@0:   nsresult CopyStringFromInput(uint32_t index, nsACString &val);
michael@0:   uint8_t ExtractByte(uint8_t bitsLeft, uint32_t &bytesConsumed);
michael@0:   nsresult CopyHuffmanStringFromInput(uint32_t index, nsACString &val);
michael@0:   nsresult DecodeHuffmanCharacter(HuffmanIncomingTable *table, uint8_t &c,
michael@0:                                   uint32_t &bytesConsumed, uint8_t &bitsLeft);
michael@0:   nsresult DecodeFinalHuffmanCharacter(HuffmanIncomingTable *table, uint8_t &c,
michael@0:                                        uint8_t &bitsLeft);
michael@0: 
michael@0:   Http2Compressor *mCompressor;
michael@0: 
michael@0:   nsCString mHeaderStatus;
michael@0:   nsCString mHeaderHost;
michael@0:   nsCString mHeaderScheme;
michael@0:   nsCString mHeaderPath;
michael@0:   nsCString mHeaderMethod;
michael@0: 
michael@0:   // state variables when DecodeBlock() is on the stack
michael@0:   uint32_t mOffset;
michael@0:   const uint8_t *mData;
michael@0:   uint32_t mDataLen;
michael@0: };
michael@0: 
michael@0: 
michael@0: class Http2Compressor MOZ_FINAL : public Http2BaseCompressor
michael@0: {
michael@0: public:
michael@0:   Http2Compressor() : mParsedContentLength(-1) { };
michael@0:   virtual ~Http2Compressor() { }
michael@0: 
michael@0:   // HTTP/1 formatted header block as input - HTTP/2 formatted
michael@0:   // header block as output
michael@0:   nsresult EncodeHeaderBlock(const nsCString &nvInput,
michael@0:                              const nsACString &method, const nsACString &path,
michael@0:                              const nsACString &host, const nsACString &scheme,
michael@0:                              nsACString &output);
michael@0: 
michael@0:   int64_t GetParsedContentLength() { return mParsedContentLength; } // -1 on not found
michael@0: 
michael@0:   void SetMaxBufferSize(uint32_t maxBufferSize);
michael@0:   nsresult SetMaxBufferSizeInternal(uint32_t maxBufferSize);
michael@0: 
michael@0: protected:
michael@0:   virtual void ClearHeaderTable() MOZ_OVERRIDE;
michael@0:   virtual void UpdateReferenceSet(int32_t delta) MOZ_OVERRIDE;
michael@0:   virtual void IncrementReferenceSetIndices() MOZ_OVERRIDE;
michael@0:   virtual void MakeRoom(uint32_t amount) MOZ_OVERRIDE;
michael@0: 
michael@0: private:
michael@0:   enum outputCode {
michael@0:     kPlainLiteral,
michael@0:     kIndexedLiteral,
michael@0:     kToggleOff,
michael@0:     kToggleOn,
michael@0:     kNop
michael@0:   };
michael@0: 
michael@0:   void DoOutput(Http2Compressor::outputCode code,
michael@0:                 const class nvPair *pair, uint32_t index);
michael@0:   void EncodeInteger(uint32_t prefixLen, uint32_t val);
michael@0:   void ProcessHeader(const nvPair inputPair);
michael@0:   void HuffmanAppend(const nsCString &value);
michael@0: 
michael@0:   int64_t mParsedContentLength;
michael@0:   uint32_t mMaxBufferSetting;
michael@0: 
michael@0:   nsAutoTArray<uint32_t, 64> mImpliedReferenceSet;
michael@0: };
michael@0: 
michael@0: } // namespace mozilla::net
michael@0: } // namespace mozilla
michael@0: 
michael@0: #endif // mozilla_net_Http2Compression_Internal_h