| // Copyright 2013 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef NET_TOOLS_BALSA_BALSA_HEADERS_H_ |
| #define NET_TOOLS_BALSA_BALSA_HEADERS_H_ |
| |
| #include <stddef.h> |
| |
| #include <algorithm> |
| #include <iosfwd> |
| #include <iterator> |
| #include <string> |
| #include <utility> |
| #include <vector> |
| |
| #include "base/logging.h" |
| #include "base/strings/string_piece.h" |
| #include "net/tools/balsa/balsa_enums.h" |
| #include "net/tools/balsa/string_piece_utils.h" |
| |
| namespace net { |
| |
| // WARNING: |
| // Note that -no- char* returned by any function in this |
| // file is null-terminated. |
| |
| // This class exists to service the specific needs of BalsaHeaders. |
| // |
| // Functional goals: |
| // 1) provide a backing-store for all of the StringPieces that BalsaHeaders |
| // returns. Every StringPiece returned from BalsaHeaders should remain |
| // valid until the BalsaHeader's object is cleared, or the header-line is |
| // erased. |
| // 2) provide a backing-store for BalsaFrame, which requires contiguous memory |
| // for its fast-path parsing functions. Note that the cost of copying is |
| // less than the cost of requiring the parser to do slow-path parsing, as |
| // it would have to check for bounds every byte, instead of every 16 bytes. |
| // |
| // This class is optimized for the case where headers are stored in one of two |
| // buffers. It doesn't make a lot of effort to densely pack memory-- in fact, |
| // it -may- be somewhat memory inefficient. This possible inefficiency allows a |
| // certain simplicity of implementation and speed which makes it worthwhile. |
| // If, in the future, better memory density is required, it should be possible |
| // to reuse the abstraction presented by this object to achieve those goals. |
| // |
| // In the most common use-case, this memory inefficiency should be relatively |
| // small. |
| // |
| // Alternate implementations of BalsaBuffer may include: |
| // - vector of strings, one per header line (similar to HTTPHeaders) |
| // - densely packed strings: |
| // - keep a sorted array/map of free-space linked lists or numbers. |
| // - use the entry that most closely first your needs. |
| // - at this point, perhaps just use a vector of strings, and let |
| // the allocator do the right thing. |
| // |
| class BalsaBuffer { |
| public: |
| static const size_t kDefaultBlocksize = 4096; |
| // We have two friends here. These exist as friends as we |
| // want to allow access to the constructors for the test |
| // class and the Balsa* classes. We put this into the |
| // header file as we want this class to be inlined into the |
| // BalsaHeaders implementation, yet be testable. |
| friend class BalsaBufferTestSpouse; |
| friend class BalsaHeaders; |
| friend class BalsaBufferTest; |
| |
| // The BufferBlock is a structure used internally by the |
| // BalsaBuffer class to store the base buffer pointers to |
| // each block, as well as the important metadata for buffer |
| // sizes and bytes free. |
| struct BufferBlock { |
| public: |
| char* buffer; |
| size_t buffer_size; |
| size_t bytes_free; |
| |
| size_t bytes_used() const { |
| return buffer_size - bytes_free; |
| } |
| char* start_of_unused_bytes() const { |
| return buffer + bytes_used(); |
| } |
| |
| BufferBlock() : buffer(NULL), buffer_size(0), bytes_free(0) {} |
| ~BufferBlock() {} |
| |
| BufferBlock(char* buf, size_t size, size_t free) : |
| buffer(buf), buffer_size(size), bytes_free(free) {} |
| // Yes we want this to be copyable (it gets stuck into vectors). |
| // For this reason, we don't use scoped ptrs, etc. here-- it |
| // is more efficient to manage this memory externally to this |
| // object. |
| }; |
| |
| typedef std::vector<BufferBlock> Blocks; |
| |
| ~BalsaBuffer(); |
| |
| // Returns the total amount of memory used by the buffer blocks. |
| size_t GetTotalBufferBlockSize() const; |
| |
| const char* GetPtr(Blocks::size_type block_idx) const { |
| DCHECK_LT(block_idx, blocks_.size()) |
| << block_idx << ", " << blocks_.size(); |
| return blocks_[block_idx].buffer; |
| } |
| |
| char* GetPtr(Blocks::size_type block_idx) { |
| DCHECK_LT(block_idx, blocks_.size()) |
| << block_idx << ", " << blocks_.size(); |
| return blocks_[block_idx].buffer; |
| } |
| |
| // This function is different from Write(), as it ensures that the data |
| // stored via subsequent calls to this function are all contiguous (and in |
| // the order in which these writes happened). This is essentially the same |
| // as a string append. |
| // |
| // You may call this function at any time between object |
| // construction/Clear(), and the calling of the |
| // NoMoreWriteToContiguousBuffer() function. |
| // |
| // You must not call this function after the NoMoreWriteToContiguousBuffer() |
| // function is called, unless a Clear() has been called since. |
| // If you do, the program will abort(). |
| // |
| // This condition is placed upon this code so that calls to Write() can |
| // append to the buffer in the first block safely, and without invaliding |
| // the StringPiece which it returns. |
| // |
| // This function's main intended user is the BalsaFrame class, which, |
| // for reasons of efficiency, requires that the buffer from which it parses |
| // the headers be contiguous. |
| // |
| void WriteToContiguousBuffer(const base::StringPiece& sp); |
| |
| void NoMoreWriteToContiguousBuffer() { |
| can_write_to_contiguous_buffer_ = false; |
| } |
| |
| // Takes a StringPiece and writes it to "permanent" storage, then returns a |
| // StringPiece which points to that data. If block_idx != NULL, it will be |
| // assigned the index of the block into which the data was stored. |
| // Note that the 'permanent' storage in which it stores data may be in |
| // the first block IFF the NoMoreWriteToContiguousBuffer function has |
| // been called since the last Clear/Construction. |
| base::StringPiece Write(const base::StringPiece& sp, |
| Blocks::size_type* block_buffer_idx); |
| |
| // Reserves "permanent" storage of the size indicated. Returns a pointer to |
| // the beginning of that storage, and assigns the index of the block used to |
| // block_buffer_idx. This function uses the first block IFF the |
| // NoMoreWriteToContiguousBuffer function has been called since the last |
| // Clear/Construction. |
| char* Reserve(size_t size, Blocks::size_type* block_buffer_idx); |
| |
| void Clear(); |
| |
| void Swap(BalsaBuffer* b); |
| |
| void CopyFrom(const BalsaBuffer& b); |
| |
| const char* StartOfFirstBlock() const { |
| return blocks_[0].buffer; |
| } |
| |
| const char* EndOfFirstBlock() const { |
| return blocks_[0].buffer + blocks_[0].bytes_used(); |
| } |
| |
| bool can_write_to_contiguous_buffer() const { |
| return can_write_to_contiguous_buffer_; |
| } |
| size_t blocksize() const { return blocksize_; } |
| Blocks::size_type num_blocks() const { return blocks_.size(); } |
| size_t buffer_size(size_t idx) const { return blocks_[idx].buffer_size; } |
| size_t bytes_used(size_t idx) const { return blocks_[idx].bytes_used(); } |
| |
| protected: |
| BalsaBuffer(); |
| |
| explicit BalsaBuffer(size_t blocksize); |
| |
| BufferBlock AllocBlock(); |
| |
| BufferBlock AllocCustomBlock(size_t blocksize); |
| |
| BufferBlock CopyBlock(const BufferBlock& b); |
| |
| // Cleans up the object. |
| // The block at start_idx, and all subsequent blocks |
| // will be cleared and have associated memory deleted. |
| void CleanupBlocksStartingFrom(Blocks::size_type start_idx); |
| |
| // A container of BufferBlocks |
| Blocks blocks_; |
| |
| // The default allocation size for a block. |
| // In general, blocksize_ bytes will be allocated for |
| // each buffer. |
| size_t blocksize_; |
| |
| // If set to true, then the first block cannot be used for Write() calls as |
| // the WriteToContiguous... function will modify the base pointer for this |
| // block, and the Write() calls need to be sure that the base pointer will |
| // not be changing in order to provide the user with StringPieces which |
| // continue to be valid. |
| bool can_write_to_contiguous_buffer_; |
| }; |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| |
| // All of the functions in the BalsaHeaders class use string pieces, by either |
| // using the StringPiece class, or giving an explicit size and char* (as these |
| // are the native representation for these string pieces). |
| // This is done for several reasons. |
| // 1) This minimizes copying/allocation/deallocation as compared to using |
| // string parameters |
| // 2) This reduces the number of strlen() calls done (as the length of any |
| // string passed in is relatively likely to be known at compile time, and for |
| // those strings passed back we obviate the need for a strlen() to determine |
| // the size of new storage allocations if a new allocation is required. |
| // 3) This class attempts to store all of its data in two linear buffers in |
| // order to enhance the speed of parsing and writing out to a buffer. As a |
| // result, many string pieces are -not- terminated by '\0', and are not |
| // c-strings. Since this is the case, we must delineate the length of the |
| // string explicitly via a length. |
| // |
| // WARNING: The side effect of using StringPiece is that if the underlying |
| // buffer changes (due to modifying the headers) the StringPieces which point |
| // to the data which was modified, may now contain "garbage", and should not |
| // be dereferenced. |
| // For example, If you fetch some component of the first-line, (request or |
| // response), and then you modify the first line, the StringPieces you |
| // originally received from the original first-line may no longer be valid). |
| // |
| // StringPieces pointing to pieces of header lines which have not been |
| // erased() or modified should be valid until the object is cleared or |
| // destroyed. |
| |
| class BalsaHeaders { |
| public: |
| struct HeaderLineDescription { |
| HeaderLineDescription(size_t first_character_index, |
| size_t key_end_index, |
| size_t value_begin_index, |
| size_t last_character_index, |
| size_t buffer_base_index) : |
| first_char_idx(first_character_index), |
| key_end_idx(key_end_index), |
| value_begin_idx(value_begin_index), |
| last_char_idx(last_character_index), |
| buffer_base_idx(buffer_base_index), |
| skip(false) {} |
| |
| HeaderLineDescription() : |
| first_char_idx(0), |
| key_end_idx(0), |
| value_begin_idx(0), |
| last_char_idx(0), |
| buffer_base_idx(0), |
| skip(false) {} |
| |
| size_t first_char_idx; |
| size_t key_end_idx; |
| size_t value_begin_idx; |
| size_t last_char_idx; |
| BalsaBuffer::Blocks::size_type buffer_base_idx; |
| bool skip; |
| }; |
| |
| typedef std::vector<base::StringPiece> HeaderTokenList; |
| friend bool ParseHTTPFirstLine(const char* begin, |
| const char* end, |
| bool is_request, |
| size_t max_request_uri_length, |
| BalsaHeaders* headers, |
| BalsaFrameEnums::ErrorCode* error_code); |
| |
| protected: |
| typedef std::vector<HeaderLineDescription> HeaderLines; |
| |
| // Why these base classes (iterator_base, reverse_iterator_base)? Well, if |
| // we do want to export both iterator and const_iterator types (currently we |
| // only have const_iterator), then this is useful to avoid code duplication. |
| // Additionally, having this base class makes comparisons of iterators of |
| // different types (they're different types to ensure that operator= and |
| // constructors do not work in the places where they're expected to not work) |
| // work properly. There could be as many as 4 iterator types, all based on |
| // the same data as iterator_base... so it makes sense to simply have some |
| // base classes. |
| |
| class iterator_base { |
| public: |
| friend class BalsaHeaders; |
| friend class reverse_iterator_base; |
| typedef std::pair<base::StringPiece, base::StringPiece> StringPiecePair; |
| typedef StringPiecePair value_type; |
| typedef value_type& reference; |
| typedef value_type* pointer; |
| |
| typedef std::forward_iterator_tag iterator_category; |
| typedef ptrdiff_t difference_type; |
| |
| typedef iterator_base self; |
| |
| // default constructor. |
| iterator_base(); |
| |
| // copy constructor. |
| iterator_base(const iterator_base& it); |
| |
| reference operator*() const { |
| return Lookup(idx_); |
| } |
| |
| pointer operator->() const { |
| return &(this->operator*()); |
| } |
| |
| bool operator==(const self& it) const { |
| return idx_ == it.idx_; |
| } |
| |
| bool operator<(const self& it) const { |
| return idx_ < it.idx_; |
| } |
| |
| bool operator<=(const self& it) const { |
| return idx_ <= it.idx_; |
| } |
| |
| bool operator!=(const self& it) const { |
| return !(*this == it); |
| } |
| |
| bool operator>(const self& it) const { |
| return it < *this; |
| } |
| |
| bool operator>=(const self& it) const { |
| return it <= *this; |
| } |
| |
| // This mainly exists so that we can have interesting output for |
| // unittesting. The EXPECT_EQ, EXPECT_NE functions require that |
| // operator<< work for the classes it sees. It would be better if there |
| // was an additional traits-like system for the gUnit output... but oh |
| // well. |
| std::ostream& operator<<(std::ostream& os) const; |
| |
| protected: |
| iterator_base(const BalsaHeaders* headers, HeaderLines::size_type index); |
| |
| void increment() { |
| const HeaderLines& header_lines = headers_->header_lines_; |
| const HeaderLines::size_type header_lines_size = header_lines.size(); |
| const HeaderLines::size_type original_idx = idx_; |
| do { |
| ++idx_; |
| } while (idx_ < header_lines_size && header_lines[idx_].skip == true); |
| // The condition below exists so that ++(end() - 1) == end(), even |
| // if there are only 'skip == true' elements between the end() iterator |
| // and the end of the vector of HeaderLineDescriptions. |
| // TODO(fenix): refactor this list so that we don't have to do |
| // linear scanning through skipped headers (and this condition is |
| // then unnecessary) |
| if (idx_ == header_lines_size) { |
| idx_ = original_idx + 1; |
| } |
| } |
| |
| void decrement() { |
| const HeaderLines& header_lines = headers_->header_lines_; |
| const HeaderLines::size_type header_lines_size = header_lines.size(); |
| const HeaderLines::size_type original_idx = idx_; |
| do { |
| --idx_; |
| } while (idx_ < header_lines_size && header_lines[idx_].skip == true); |
| // The condition below exists so that --(rbegin() + 1) == rbegin(), even |
| // if there are only 'skip == true' elements between the rbegin() iterator |
| // and the beginning of the vector of HeaderLineDescriptions. |
| // TODO(fenix): refactor this list so that we don't have to do |
| // linear scanning through skipped headers (and this condition is |
| // then unnecessary) |
| if (idx_ > header_lines_size) { |
| idx_ = original_idx - 1; |
| } |
| } |
| |
| reference Lookup(HeaderLines::size_type index) const { |
| DCHECK_LT(index, headers_->header_lines_.size()); |
| const HeaderLineDescription& line = headers_->header_lines_[index]; |
| const char* stream_begin = headers_->GetPtr(line.buffer_base_idx); |
| value_ = value_type( |
| base::StringPiece(stream_begin + line.first_char_idx, |
| line.key_end_idx - line.first_char_idx), |
| base::StringPiece(stream_begin + line.value_begin_idx, |
| line.last_char_idx - line.value_begin_idx)); |
| DCHECK_GE(line.key_end_idx, line.first_char_idx); |
| DCHECK_GE(line.last_char_idx, line.value_begin_idx); |
| return value_; |
| } |
| |
| const BalsaHeaders* headers_; |
| HeaderLines::size_type idx_; |
| mutable StringPiecePair value_; |
| }; |
| |
| class reverse_iterator_base : public iterator_base { |
| public: |
| typedef reverse_iterator_base self; |
| typedef iterator_base::reference reference; |
| typedef iterator_base::pointer pointer; |
| using iterator_base::headers_; |
| using iterator_base::idx_; |
| |
| reverse_iterator_base() : iterator_base() {} |
| |
| // This constructor is no explicit purposely. |
| reverse_iterator_base(const iterator_base& it) : // NOLINT |
| iterator_base(it) { |
| } |
| |
| self& operator=(const iterator_base& it) { |
| idx_ = it.idx_; |
| headers_ = it.headers_; |
| return *this; |
| } |
| |
| self& operator=(const reverse_iterator_base& it) { |
| idx_ = it.idx_; |
| headers_ = it.headers_; |
| return *this; |
| } |
| |
| reference operator*() const { |
| return Lookup(idx_ - 1); |
| } |
| |
| pointer operator->() const { |
| return &(this->operator*()); |
| } |
| |
| reverse_iterator_base(const reverse_iterator_base& it) : |
| iterator_base(it) { } |
| |
| protected: |
| void increment() { |
| --idx_; |
| iterator_base::decrement(); |
| ++idx_; |
| } |
| |
| void decrement() { |
| ++idx_; |
| iterator_base::increment(); |
| --idx_; |
| } |
| |
| reverse_iterator_base(const BalsaHeaders* headers, |
| HeaderLines::size_type index) : |
| iterator_base(headers, index) {} |
| }; |
| |
| public: |
| class const_header_lines_iterator : public iterator_base { |
| friend class BalsaHeaders; |
| public: |
| typedef const_header_lines_iterator self; |
| const_header_lines_iterator() : iterator_base() {} |
| |
| const_header_lines_iterator(const const_header_lines_iterator& it) : |
| iterator_base(it.headers_, it.idx_) {} |
| |
| self& operator++() { |
| iterator_base::increment(); |
| return *this; |
| } |
| |
| self& operator--() { |
| iterator_base::decrement(); |
| return *this; |
| } |
| protected: |
| const_header_lines_iterator(const BalsaHeaders* headers, |
| HeaderLines::size_type index) : |
| iterator_base(headers, index) {} |
| }; |
| |
| class const_reverse_header_lines_iterator : public reverse_iterator_base { |
| public: |
| typedef const_reverse_header_lines_iterator self; |
| const_reverse_header_lines_iterator() : reverse_iterator_base() {} |
| |
| const_reverse_header_lines_iterator( |
| const const_header_lines_iterator& it) : |
| reverse_iterator_base(it.headers_, it.idx_) {} |
| |
| const_reverse_header_lines_iterator( |
| const const_reverse_header_lines_iterator& it) : |
| reverse_iterator_base(it.headers_, it.idx_) {} |
| |
| const_header_lines_iterator base() { |
| return const_header_lines_iterator(headers_, idx_); |
| } |
| |
| self& operator++() { |
| reverse_iterator_base::increment(); |
| return *this; |
| } |
| |
| self& operator--() { |
| reverse_iterator_base::decrement(); |
| return *this; |
| } |
| protected: |
| const_reverse_header_lines_iterator(const BalsaHeaders* headers, |
| HeaderLines::size_type index) : |
| reverse_iterator_base(headers, index) {} |
| |
| friend class BalsaHeaders; |
| }; |
| |
| // An iterator that only stops at lines with a particular key. |
| // See also GetIteratorForKey. |
| // |
| // Check against header_lines_key_end() to determine when iteration is |
| // finished. header_lines_end() will also work. |
| class const_header_lines_key_iterator : public iterator_base { |
| friend class BalsaHeaders; |
| public: |
| typedef const_header_lines_key_iterator self; |
| const_header_lines_key_iterator(const const_header_lines_key_iterator&); |
| |
| self& operator++() { |
| do { |
| iterator_base::increment(); |
| } while (!AtEnd() && |
| !base::EqualsCaseInsensitiveASCII(key_, (**this).first)); |
| return *this; |
| } |
| |
| void operator++(int ignore) { |
| ++(*this); |
| } |
| |
| // Only forward-iteration makes sense, so no operator-- defined. |
| |
| private: |
| const_header_lines_key_iterator(const BalsaHeaders* headers, |
| HeaderLines::size_type index, |
| const base::StringPiece& key); |
| |
| // Should only be used for creating an end iterator. |
| const_header_lines_key_iterator(const BalsaHeaders* headers, |
| HeaderLines::size_type index); |
| |
| bool AtEnd() const { |
| return *this >= headers_->header_lines_end(); |
| } |
| |
| base::StringPiece key_; |
| }; |
| |
| // TODO(fenix): Revisit the amount of bytes initially allocated to the second |
| // block of the balsa_buffer_. It may make sense to pre-allocate some amount |
| // (roughly the amount we'd append in new headers such as X-User-Ip, etc.) |
| BalsaHeaders(); |
| ~BalsaHeaders(); |
| |
| const_header_lines_iterator header_lines_begin() { |
| return HeaderLinesBeginHelper<const_header_lines_iterator>(); |
| } |
| |
| const_header_lines_iterator header_lines_begin() const { |
| return HeaderLinesBeginHelper<const_header_lines_iterator>(); |
| } |
| |
| const_header_lines_iterator header_lines_end() { |
| return HeaderLinesEndHelper<const_header_lines_iterator>(); |
| } |
| |
| const_header_lines_iterator header_lines_end() const { |
| return HeaderLinesEndHelper<const_header_lines_iterator>(); |
| } |
| |
| const_reverse_header_lines_iterator header_lines_rbegin() { |
| return const_reverse_header_lines_iterator(header_lines_end()); |
| } |
| |
| const_reverse_header_lines_iterator header_lines_rbegin() const { |
| return const_reverse_header_lines_iterator(header_lines_end()); |
| } |
| |
| const_reverse_header_lines_iterator header_lines_rend() { |
| return const_reverse_header_lines_iterator(header_lines_begin()); |
| } |
| |
| const_reverse_header_lines_iterator header_lines_rend() const { |
| return const_reverse_header_lines_iterator(header_lines_begin()); |
| } |
| |
| const_header_lines_key_iterator header_lines_key_end() const { |
| return HeaderLinesEndHelper<const_header_lines_key_iterator>(); |
| } |
| |
| void erase(const const_header_lines_iterator& it) { |
| DCHECK_EQ(it.headers_, this); |
| DCHECK_LT(it.idx_, header_lines_.size()); |
| DCHECK_GE(it.idx_, 0u); |
| header_lines_[it.idx_].skip = true; |
| } |
| |
| void Clear(); |
| |
| void Swap(BalsaHeaders* other); |
| |
| void CopyFrom(const BalsaHeaders& other); |
| |
| void HackHeader(const base::StringPiece& key, const base::StringPiece& value); |
| |
| // Same as AppendToHeader, except that it will attempt to preserve |
| // header ordering. |
| // Note that this will always append to an existing header, if available, |
| // without moving the header around, or collapsing multiple header lines |
| // with the same key together. For this reason, it only 'attempts' to |
| // preserve header ordering. |
| // TODO(fenix): remove this function and rename all occurances |
| // of it in the code to AppendToHeader when the condition above |
| // has been satisified. |
| void HackAppendToHeader(const base::StringPiece& key, |
| const base::StringPiece& value); |
| |
| // Replaces header entries with key 'key' if they exist, or appends |
| // a new header if none exist. See 'AppendHeader' below for additional |
| // comments about ContentLength and TransferEncoding headers. Note that this |
| // will allocate new storage every time that it is called. |
| // TODO(fenix): modify this function to reuse existing storage |
| // if it is available. |
| void ReplaceOrAppendHeader(const base::StringPiece& key, |
| const base::StringPiece& value); |
| |
| // Append a new header entry to the header object. Clients who wish to append |
| // Content-Length header should use SetContentLength() method instead of |
| // adding the content length header using AppendHeader (manually adding the |
| // content length header will not update the content_length_ and |
| // content_length_status_ values). |
| // Similarly, clients who wish to add or remove the transfer encoding header |
| // in order to apply or remove chunked encoding should use SetChunkEncoding() |
| // instead. |
| void AppendHeader(const base::StringPiece& key, |
| const base::StringPiece& value); |
| |
| // Appends ',value' to an existing header named 'key'. If no header with the |
| // correct key exists, it will call AppendHeader(key, value). Calling this |
| // function on a key which exists several times in the headers will produce |
| // unpredictable results. |
| void AppendToHeader(const base::StringPiece& key, |
| const base::StringPiece& value); |
| |
| // Prepends 'value,' to an existing header named 'key'. If no header with the |
| // correct key exists, it will call AppendHeader(key, value). Calling this |
| // function on a key which exists several times in the headers will produce |
| // unpredictable results. |
| void PrependToHeader(const base::StringPiece& key, |
| const base::StringPiece& value); |
| |
| const base::StringPiece GetHeader(const base::StringPiece& key) const; |
| |
| // Iterates over all currently valid header lines, appending their |
| // values into the vector 'out', in top-to-bottom order. |
| // Header-lines which have been erased are not currently valid, and |
| // will not have their values appended. Empty values will be |
| // represented as empty string. If 'key' doesn't exist in the headers at |
| // all, out will not be changed. We do not clear the vector out |
| // before adding new entries. If there are header lines with matching |
| // key but empty value then they are also added to the vector out. |
| // (Basically empty values are not treated in any special manner). |
| // |
| // Example: |
| // Input header: |
| // "GET / HTTP/1.0\r\n" |
| // "key1: v1\r\n" |
| // "key1: \r\n" |
| // "key1:\r\n" |
| // "key1: v1\r\n" |
| // "key1:v2\r\n" |
| // |
| // vector out is initially: ["foo"] |
| // vector out after GetAllOfHeader("key1", &out) is: |
| // ["foo", "v1", "", "", "v2", "v1", "v2"] |
| |
| void GetAllOfHeader(const base::StringPiece& key, |
| std::vector<base::StringPiece>* out) const; |
| |
| // Joins all values for key into a comma-separated string in out. |
| // More efficient than calling JoinStrings on result of GetAllOfHeader if |
| // you don't need the intermediate vector<StringPiece>. |
| void GetAllOfHeaderAsString(const base::StringPiece& key, |
| std::string* out) const; |
| |
| // Returns true if RFC 2616 Section 14 indicates that header can |
| // have multiple values. |
| static bool IsMultivaluedHeader(const base::StringPiece& header); |
| |
| // Determine if a given header is present. |
| inline bool HasHeader(const base::StringPiece& key) const { |
| return (GetConstHeaderLinesIterator(key, header_lines_.begin()) != |
| header_lines_.end()); |
| } |
| |
| // Returns true iff any header 'key' exists with non-empty value. |
| bool HasNonEmptyHeader(const base::StringPiece& key) const; |
| |
| const_header_lines_iterator GetHeaderPosition( |
| const base::StringPiece& key) const; |
| |
| // Returns a forward-only iterator that only stops at lines matching key. |
| // String backing 'key' must remain valid for lifetime of iterator. |
| // |
| // Check returned iterator against header_lines_key_end() to determine when |
| // iteration is finished. |
| const_header_lines_key_iterator GetIteratorForKey( |
| const base::StringPiece& key) const; |
| |
| void RemoveAllOfHeader(const base::StringPiece& key); |
| |
| // Removes all headers starting with 'key' [case insensitive] |
| void RemoveAllHeadersWithPrefix(const base::StringPiece& key); |
| |
| // Returns the lower bound of memory used by this header object, including |
| // all internal buffers and data structure. Some of the memory used cannot be |
| // directly measure. For example, memory used for bookkeeping by standard |
| // containers. |
| size_t GetMemoryUsedLowerBound() const; |
| |
| // Returns the upper bound on the required buffer space to fully write out |
| // the header object (this include the first line, all header lines, and the |
| // final CRLF that marks the ending of the header). |
| size_t GetSizeForWriteBuffer() const; |
| |
| // The following WriteHeader* methods are template member functions that |
| // place one requirement on the Buffer class: it must implement a Write |
| // method that takes a pointer and a length. The buffer passed in is not |
| // required to be stretchable. For non-stretchable buffers, the user must |
| // call GetSizeForWriteBuffer() to find out the upper bound on the output |
| // buffer space required to make sure that the entire header is serialized. |
| // BalsaHeaders will not check that there is adequate space in the buffer |
| // object during the write. |
| |
| // Writes the entire header and the final CRLF that marks the end of the HTTP |
| // header section to the buffer. After this method returns, no more header |
| // data should be written to the buffer. |
| template <typename Buffer> |
| void WriteHeaderAndEndingToBuffer(Buffer* buffer) const { |
| WriteToBuffer(buffer); |
| WriteHeaderEndingToBuffer(buffer); |
| } |
| |
| // Writes the final CRLF to the buffer to terminate the HTTP header section. |
| // After this method returns, no more header data should be written to the |
| // buffer. |
| template <typename Buffer> |
| static void WriteHeaderEndingToBuffer(Buffer* buffer) { |
| buffer->Write("\r\n", 2); |
| } |
| |
| // Writes the entire header to the buffer without the CRLF that terminates |
| // the HTTP header. This lets users append additional header lines using |
| // WriteHeaderLineToBuffer and then terminate the header with |
| // WriteHeaderEndingToBuffer as the header is serialized to the |
| // buffer, without having to first copy the header. |
| template <typename Buffer> |
| void WriteToBuffer(Buffer* buffer) const { |
| // write the first line. |
| const size_t firstline_len = whitespace_4_idx_ - non_whitespace_1_idx_; |
| const char* stream_begin = GetPtr(firstline_buffer_base_idx_); |
| buffer->Write(stream_begin + non_whitespace_1_idx_, firstline_len); |
| buffer->Write("\r\n", 2); |
| const HeaderLines::size_type end = header_lines_.size(); |
| for (HeaderLines::size_type i = 0; i < end; ++i) { |
| const HeaderLineDescription& line = header_lines_[i]; |
| if (line.skip) { |
| continue; |
| } |
| const char* line_ptr = GetPtr(line.buffer_base_idx); |
| WriteHeaderLineToBuffer( |
| buffer, |
| base::StringPiece(line_ptr + line.first_char_idx, |
| line.key_end_idx - line.first_char_idx), |
| base::StringPiece(line_ptr + line.value_begin_idx, |
| line.last_char_idx - line.value_begin_idx)); |
| } |
| } |
| |
| // Takes a header line in the form of a key/value pair and append it to the |
| // buffer. This function should be called after WriteToBuffer to |
| // append additional header lines to the header without copying the header. |
| // When the user is done with appending to the buffer, |
| // WriteHeaderEndingToBuffer must be used to terminate the HTTP |
| // header in the buffer. This method is a no-op if key is empty. |
| template <typename Buffer> |
| static void WriteHeaderLineToBuffer(Buffer* buffer, |
| const base::StringPiece& key, |
| const base::StringPiece& value) { |
| // if the key is empty, we don't want to write the rest because it |
| // will not be a well-formed header line. |
| if (!key.empty()) { |
| buffer->Write(key.data(), key.size()); |
| buffer->Write(": ", 2); |
| buffer->Write(value.data(), value.size()); |
| buffer->Write("\r\n", 2); |
| } |
| } |
| |
| // Dump the textural representation of the header object to a string, which |
| // is suitable for writing out to logs. All CRLF will be printed out as \n. |
| // This function can be called on a header object in any state. The header |
| // content is appended to the string; the original content is not cleared. |
| void DumpHeadersToString(std::string* str) const; |
| |
| // Calls DumpHeadersToString to dump the textural representation of the header |
| // object to a string. Raw header data will be printed out if the header |
| // object is not completely parsed, e.g., when there was an error in the |
| // middle of parsing. |
| void DumpToString(std::string* str) const; |
| |
| const base::StringPiece first_line() const { |
| DCHECK_GE(whitespace_4_idx_, non_whitespace_1_idx_); |
| return base::StringPiece(BeginningOfFirstLine() + non_whitespace_1_idx_, |
| whitespace_4_idx_ - non_whitespace_1_idx_); |
| } |
| |
| // Returns the parsed value of the response code if it has been parsed. |
| // Guaranteed to return 0 when unparsed (though it is a much better idea to |
| // verify that the BalsaFrame had no errors while parsing). |
| // This may return response codes which are outside the normal bounds of |
| // HTTP response codes-- it is up to the user of this class to ensure that |
| // the response code is one which is interpretable. |
| size_t parsed_response_code() const { return parsed_response_code_; } |
| |
| const base::StringPiece request_method() const { |
| DCHECK_GE(whitespace_2_idx_, non_whitespace_1_idx_); |
| return base::StringPiece(BeginningOfFirstLine() + non_whitespace_1_idx_, |
| whitespace_2_idx_ - non_whitespace_1_idx_); |
| } |
| |
| const base::StringPiece response_version() const { |
| // Note: There is no difference between request_method() and |
| // response_version(). They both could be called |
| // GetFirstTokenFromFirstline()... but that wouldn't be anywhere near as |
| // descriptive. |
| return request_method(); |
| } |
| |
| const base::StringPiece request_uri() const { |
| DCHECK_GE(whitespace_3_idx_, non_whitespace_2_idx_); |
| return base::StringPiece(BeginningOfFirstLine() + non_whitespace_2_idx_, |
| whitespace_3_idx_ - non_whitespace_2_idx_); |
| } |
| |
| const base::StringPiece response_code() const { |
| // Note: There is no difference between request_uri() and response_code(). |
| // They both could be called GetSecondtTokenFromFirstline(), but, as noted |
| // in an earlier comment, that wouldn't be as descriptive. |
| return request_uri(); |
| } |
| |
| const base::StringPiece request_version() const { |
| DCHECK_GE(whitespace_4_idx_, non_whitespace_3_idx_); |
| return base::StringPiece(BeginningOfFirstLine() + non_whitespace_3_idx_, |
| whitespace_4_idx_ - non_whitespace_3_idx_); |
| } |
| |
| const base::StringPiece response_reason_phrase() const { |
| // Note: There is no difference between request_version() and |
| // response_reason_phrase(). They both could be called |
| // GetThirdTokenFromFirstline(), but, as noted in an earlier comment, that |
| // wouldn't be as descriptive. |
| return request_version(); |
| } |
| |
| // Note that SetFirstLine will not update the internal indices for the |
| // various bits of the first-line (and may set them all to zero). |
| // If you'd like to use the accessors for the various bits of the firstline, |
| // then you should use the Set* functions, or SetFirstlineFromStringPieces, |
| // below, instead. |
| // |
| void SetFirstlineFromStringPieces(const base::StringPiece& firstline_a, |
| const base::StringPiece& firstline_b, |
| const base::StringPiece& firstline_c); |
| |
| void SetRequestFirstlineFromStringPieces(const base::StringPiece& method, |
| const base::StringPiece& uri, |
| const base::StringPiece& version) { |
| SetFirstlineFromStringPieces(method, uri, version); |
| } |
| |
| void SetResponseFirstlineFromStringPieces( |
| const base::StringPiece& version, |
| const base::StringPiece& code, |
| const base::StringPiece& reason_phrase) { |
| SetFirstlineFromStringPieces(version, code, reason_phrase); |
| } |
| |
| // These functions are exactly the same, except that their names are |
| // different. This is done so that the code using this class is more |
| // expressive. |
| void SetRequestMethod(const base::StringPiece& method); |
| void SetResponseVersion(const base::StringPiece& version); |
| |
| void SetRequestUri(const base::StringPiece& uri); |
| void SetResponseCode(const base::StringPiece& code); |
| void set_parsed_response_code(size_t parsed_response_code) { |
| parsed_response_code_ = parsed_response_code; |
| } |
| void SetParsedResponseCodeAndUpdateFirstline(size_t parsed_response_code); |
| |
| // These functions are exactly the same, except that their names are |
| // different. This is done so that the code using this class is more |
| // expressive. |
| void SetRequestVersion(const base::StringPiece& version); |
| void SetResponseReasonPhrase(const base::StringPiece& reason_phrase); |
| |
| // The biggest problem with SetFirstLine is that we don't want to use a |
| // separate buffer for it. The second biggest problem with it is that the |
| // first biggest problem requires that we store offsets into a buffer instead |
| // of pointers into a buffer. Cuteness aside, SetFirstLine doesn't parse |
| // the individual fields of the firstline, and so accessors to those fields |
| // will not work properly after calling SetFirstLine. If you want those |
| // accessors to work, use the Set* functions above this one. |
| // SetFirstLine is stuff useful, however, if all you care about is correct |
| // serialization with the rest of the header object. |
| void SetFirstLine(const base::StringPiece& line); |
| |
| // Simple accessors to some of the internal state |
| bool transfer_encoding_is_chunked() const { |
| return transfer_encoding_is_chunked_; |
| } |
| |
| static bool ResponseCodeImpliesNoBody(size_t code) { |
| // From HTTP spec section 6.1.1 all 1xx responses must not have a body, |
| // as well as 204 No Content and 304 Not Modified. |
| return ((code >= 100) && (code <= 199)) || (code == 204) || (code == 304); |
| } |
| |
| // Note: never check this for requests. Nothing bad will happen if you do, |
| // but spec does not allow requests framed by connection close. |
| // TODO(vitaliyl): refactor. |
| bool is_framed_by_connection_close() const { |
| // We declare that response is framed by connection close if it has no |
| // content-length, no transfer encoding, and is allowed to have a body by |
| // the HTTP spec. |
| // parsed_response_code_ is 0 for requests, so ResponseCodeImpliesNoBody |
| // will return false. |
| return (content_length_status_ == BalsaHeadersEnums::NO_CONTENT_LENGTH) && |
| !transfer_encoding_is_chunked_ && |
| !ResponseCodeImpliesNoBody(parsed_response_code_); |
| } |
| |
| size_t content_length() const { return content_length_; } |
| BalsaHeadersEnums::ContentLengthStatus content_length_status() const { |
| return content_length_status_; |
| } |
| |
| // SetContentLength and SetChunkEncoding modifies the header object to use |
| // content-length and transfer-encoding headers in a consistent manner. They |
| // set all internal flags and status so client can get a consistent view from |
| // various accessors. |
| void SetContentLength(size_t length); |
| void SetChunkEncoding(bool chunk_encode); |
| |
| protected: |
| friend class BalsaFrame; |
| friend class SpdyFrame; |
| friend class HTTPMessage; |
| friend class BalsaHeadersTokenUtils; |
| |
| const char* BeginningOfFirstLine() const { |
| return GetPtr(firstline_buffer_base_idx_); |
| } |
| |
| char* GetPtr(BalsaBuffer::Blocks::size_type block_idx) { |
| return balsa_buffer_.GetPtr(block_idx); |
| } |
| |
| const char* GetPtr(BalsaBuffer::Blocks::size_type block_idx) const { |
| return balsa_buffer_.GetPtr(block_idx); |
| } |
| |
| void WriteFromFramer(const char* ptr, size_t size) { |
| balsa_buffer_.WriteToContiguousBuffer(base::StringPiece(ptr, size)); |
| } |
| |
| void DoneWritingFromFramer() { |
| balsa_buffer_.NoMoreWriteToContiguousBuffer(); |
| } |
| |
| const char* OriginalHeaderStreamBegin() const { |
| return balsa_buffer_.StartOfFirstBlock(); |
| } |
| |
| const char* OriginalHeaderStreamEnd() const { |
| return balsa_buffer_.EndOfFirstBlock(); |
| } |
| |
| size_t GetReadableBytesFromHeaderStream() const { |
| return OriginalHeaderStreamEnd() - OriginalHeaderStreamBegin(); |
| } |
| |
| void GetReadablePtrFromHeaderStream(const char** p, size_t* s) { |
| *p = OriginalHeaderStreamBegin(); |
| *s = GetReadableBytesFromHeaderStream(); |
| } |
| |
| base::StringPiece GetValueFromHeaderLineDescription( |
| const HeaderLineDescription& line) const; |
| |
| void AddAndMakeDescription(const base::StringPiece& key, |
| const base::StringPiece& value, |
| HeaderLineDescription* d); |
| |
| void AppendOrPrependAndMakeDescription(const base::StringPiece& key, |
| const base::StringPiece& value, |
| bool append, |
| HeaderLineDescription* d); |
| |
| // Removes all header lines with the given key starting at start. |
| void RemoveAllOfHeaderStartingAt(const base::StringPiece& key, |
| HeaderLines::iterator start); |
| |
| // If the 'key' does not exist in the headers, calls |
| // AppendHeader(key, value). Otherwise if append is true, appends ',value' |
| // to the first existing header with key 'key'. If append is false, prepends |
| // 'value,' to the first existing header with key 'key'. |
| void AppendOrPrependToHeader(const base::StringPiece& key, |
| const base::StringPiece& value, |
| bool append); |
| |
| HeaderLines::const_iterator GetConstHeaderLinesIterator( |
| const base::StringPiece& key, |
| HeaderLines::const_iterator start) const; |
| |
| HeaderLines::iterator GetHeaderLinesIteratorNoSkip( |
| const base::StringPiece& key, |
| HeaderLines::iterator start); |
| |
| HeaderLines::iterator GetHeaderLinesIterator( |
| const base::StringPiece& key, |
| HeaderLines::iterator start); |
| |
| template <typename IteratorType> |
| const IteratorType HeaderLinesBeginHelper() const { |
| if (header_lines_.empty()) { |
| return IteratorType(this, 0); |
| } |
| const HeaderLines::size_type header_lines_size = header_lines_.size(); |
| for (HeaderLines::size_type i = 0; i < header_lines_size; ++i) { |
| if (header_lines_[i].skip == false) { |
| return IteratorType(this, i); |
| } |
| } |
| return IteratorType(this, 0); |
| } |
| |
| template <typename IteratorType> |
| const IteratorType HeaderLinesEndHelper() const { |
| if (header_lines_.empty()) { |
| return IteratorType(this, 0); |
| } |
| const HeaderLines::size_type header_lines_size = header_lines_.size(); |
| HeaderLines::size_type i = header_lines_size; |
| do { |
| --i; |
| if (header_lines_[i].skip == false) { |
| return IteratorType(this, i + 1); |
| } |
| } while (i != 0); |
| return IteratorType(this, 0); |
| } |
| |
| // At the moment, this function will always return the original headers. |
| // In the future, it may not do so after erasing header lines, modifying |
| // header lines, or modifying the first line. |
| // For this reason, it is strongly suggested that use of this function is |
| // only acceptable for the purpose of debugging parse errors seen by the |
| // BalsaFrame class. |
| base::StringPiece OriginalHeadersForDebugging() const { |
| return base::StringPiece(OriginalHeaderStreamBegin(), |
| OriginalHeaderStreamEnd() - OriginalHeaderStreamBegin()); |
| } |
| |
| BalsaBuffer balsa_buffer_; |
| |
| size_t content_length_; |
| BalsaHeadersEnums::ContentLengthStatus content_length_status_; |
| size_t parsed_response_code_; |
| // HTTP firstlines all have the following structure: |
| // LWS NONWS LWS NONWS LWS NONWS NOTCRLF CRLF |
| // [\t \r\n]+ [^\t ]+ [\t ]+ [^\t ]+ [\t ]+ [^\t ]+ [^\r\n]+ "\r\n" |
| // ws1 nws1 ws2 nws2 ws3 nws3 ws4 |
| // | [-------) [-------) [----------------) |
| // REQ: method request_uri version |
| // RESP: version statuscode reason |
| // |
| // The first NONWS->LWS component we'll call firstline_a. |
| // The second firstline_b, and the third firstline_c. |
| // |
| // firstline_a goes from nws1 to (but not including) ws2 |
| // firstline_b goes from nws2 to (but not including) ws3 |
| // firstline_c goes from nws3 to (but not including) ws4 |
| // |
| // In the code: |
| // ws1 == whitespace_1_idx_ |
| // nws1 == non_whitespace_1_idx_ |
| // ws2 == whitespace_2_idx_ |
| // nws2 == non_whitespace_2_idx_ |
| // ws3 == whitespace_3_idx_ |
| // nws3 == non_whitespace_3_idx_ |
| // ws4 == whitespace_4_idx_ |
| BalsaBuffer::Blocks::size_type firstline_buffer_base_idx_; |
| size_t whitespace_1_idx_; |
| size_t non_whitespace_1_idx_; |
| size_t whitespace_2_idx_; |
| size_t non_whitespace_2_idx_; |
| size_t whitespace_3_idx_; |
| size_t non_whitespace_3_idx_; |
| size_t whitespace_4_idx_; |
| size_t end_of_firstline_idx_; |
| |
| bool transfer_encoding_is_chunked_; |
| |
| HeaderLines header_lines_; |
| }; |
| |
| } // namespace net |
| |
| #endif // NET_TOOLS_BALSA_BALSA_HEADERS_H_ |