blob: a625393326c354c01c41ea2b5415e5442c27229b [file] [log] [blame]
// Copyright (c) 2012 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 QUICHE_SPDY_CORE_SPDY_HEADER_BLOCK_H_
#define QUICHE_SPDY_CORE_SPDY_HEADER_BLOCK_H_
#include <stddef.h>
#include <functional>
#include <list>
#include <string>
#include <utility>
#include <vector>
#include "net/third_party/quiche/src/common/platform/api/quiche_string_piece.h"
#include "net/third_party/quiche/src/spdy/core/spdy_header_storage.h"
#include "net/third_party/quiche/src/spdy/platform/api/spdy_containers.h"
#include "net/third_party/quiche/src/spdy/platform/api/spdy_export.h"
#include "net/third_party/quiche/src/spdy/platform/api/spdy_macros.h"
#include "net/third_party/quiche/src/spdy/platform/api/spdy_string_utils.h"
namespace spdy {
namespace test {
class SpdyHeaderBlockPeer;
class ValueProxyPeer;
} // namespace test
// This class provides a key-value map that can be used to store SPDY header
// names and values. This data structure preserves insertion order.
//
// Under the hood, this data structure uses large, contiguous blocks of memory
// to store names and values. Lookups may be performed with QuicheStringPiece
// keys, and values are returned as QuicheStringPieces (via ValueProxy, below).
// Value QuicheStringPieces are valid as long as the SpdyHeaderBlock exists;
// allocated memory is never freed until SpdyHeaderBlock's destruction.
//
// This implementation does not make much of an effort to minimize wasted space.
// It's expected that keys are rarely deleted from a SpdyHeaderBlock.
class SPDY_EXPORT_PRIVATE SpdyHeaderBlock {
private:
// Stores a list of value fragments that can be joined later with a
// key-dependent separator.
class SPDY_EXPORT_PRIVATE HeaderValue {
public:
HeaderValue(SpdyHeaderStorage* storage,
quiche::QuicheStringPiece key,
quiche::QuicheStringPiece initial_value);
// Moves are allowed.
HeaderValue(HeaderValue&& other);
HeaderValue& operator=(HeaderValue&& other);
void set_storage(SpdyHeaderStorage* storage);
// Copies are not.
HeaderValue(const HeaderValue& other) = delete;
HeaderValue& operator=(const HeaderValue& other) = delete;
~HeaderValue();
// Consumes at most |fragment.size()| bytes of memory.
void Append(quiche::QuicheStringPiece fragment);
quiche::QuicheStringPiece value() const { return as_pair().second; }
const std::pair<quiche::QuicheStringPiece, quiche::QuicheStringPiece>&
as_pair() const;
// Size estimate including separators. Used when keys are erased from
// SpdyHeaderBlock.
size_t SizeEstimate() const { return size_; }
private:
// May allocate a large contiguous region of memory to hold the concatenated
// fragments and separators.
quiche::QuicheStringPiece ConsolidatedValue() const;
mutable SpdyHeaderStorage* storage_;
mutable std::vector<quiche::QuicheStringPiece> fragments_;
// The first element is the key; the second is the consolidated value.
mutable std::pair<quiche::QuicheStringPiece, quiche::QuicheStringPiece>
pair_;
size_t size_ = 0;
size_t separator_size_ = 0;
};
typedef SpdyLinkedHashMap<quiche::QuicheStringPiece,
HeaderValue,
SpdyStringPieceCaseHash,
SpdyStringPieceCaseEq>
MapType;
public:
typedef std::pair<quiche::QuicheStringPiece, quiche::QuicheStringPiece>
value_type;
// Provides iteration over a sequence of std::pair<QuicheStringPiece,
// QuicheStringPiece>, even though the underlying MapType::value_type is
// different. Dereferencing the iterator will result in memory allocation for
// multi-value headers.
class SPDY_EXPORT_PRIVATE iterator {
public:
// The following type definitions fulfill the requirements for iterator
// implementations.
typedef std::pair<quiche::QuicheStringPiece, quiche::QuicheStringPiece>
value_type;
typedef value_type& reference;
typedef value_type* pointer;
typedef std::forward_iterator_tag iterator_category;
typedef MapType::iterator::difference_type difference_type;
// In practice, this iterator only offers access to const value_type.
typedef const value_type& const_reference;
typedef const value_type* const_pointer;
explicit iterator(MapType::const_iterator it);
iterator(const iterator& other);
~iterator();
// This will result in memory allocation if the value consists of multiple
// fragments.
const_reference operator*() const { return it_->second.as_pair(); }
const_pointer operator->() const { return &(this->operator*()); }
bool operator==(const iterator& it) const { return it_ == it.it_; }
bool operator!=(const iterator& it) const { return !(*this == it); }
iterator& operator++() {
it_++;
return *this;
}
iterator operator++(int) {
auto ret = *this;
this->operator++();
return ret;
}
private:
MapType::const_iterator it_;
};
typedef iterator const_iterator;
SpdyHeaderBlock();
SpdyHeaderBlock(const SpdyHeaderBlock& other) = delete;
SpdyHeaderBlock(SpdyHeaderBlock&& other);
~SpdyHeaderBlock();
SpdyHeaderBlock& operator=(const SpdyHeaderBlock& other) = delete;
SpdyHeaderBlock& operator=(SpdyHeaderBlock&& other);
SpdyHeaderBlock Clone() const;
bool operator==(const SpdyHeaderBlock& other) const;
bool operator!=(const SpdyHeaderBlock& other) const;
// Provides a human readable multi-line representation of the stored header
// keys and values.
std::string DebugString() const;
iterator begin() { return iterator(map_.begin()); }
iterator end() { return iterator(map_.end()); }
const_iterator begin() const { return const_iterator(map_.begin()); }
const_iterator end() const { return const_iterator(map_.end()); }
bool empty() const { return map_.empty(); }
size_t size() const { return map_.size(); }
iterator find(quiche::QuicheStringPiece key) {
return iterator(map_.find(key));
}
const_iterator find(quiche::QuicheStringPiece key) const {
return const_iterator(map_.find(key));
}
void erase(quiche::QuicheStringPiece key);
// Clears both our MapType member and the memory used to hold headers.
void clear();
// The next few methods copy data into our backing storage.
// If key already exists in the block, replaces the value of that key. Else
// adds a new header to the end of the block.
void insert(const value_type& value);
// If a header with the key is already present, then append the value to the
// existing header value, NUL ("\0") separated unless the key is cookie, in
// which case the separator is "; ".
// If there is no such key, a new header with the key and value is added.
void AppendValueOrAddHeader(const quiche::QuicheStringPiece key,
const quiche::QuicheStringPiece value);
// This object provides automatic conversions that allow SpdyHeaderBlock to be
// nearly a drop-in replacement for
// SpdyLinkedHashMap<std::string, std::string>.
// It reads data from or writes data to a SpdyHeaderStorage.
class SPDY_EXPORT_PRIVATE ValueProxy {
public:
~ValueProxy();
// Moves are allowed.
ValueProxy(ValueProxy&& other);
ValueProxy& operator=(ValueProxy&& other);
// Copies are not.
ValueProxy(const ValueProxy& other) = delete;
ValueProxy& operator=(const ValueProxy& other) = delete;
// Assignment modifies the underlying SpdyHeaderBlock.
ValueProxy& operator=(quiche::QuicheStringPiece value);
// Provides easy comparison against QuicheStringPiece.
bool operator==(quiche::QuicheStringPiece value) const;
std::string as_string() const;
private:
friend class SpdyHeaderBlock;
friend class test::ValueProxyPeer;
ValueProxy(SpdyHeaderBlock* block,
SpdyHeaderBlock::MapType::iterator lookup_result,
const quiche::QuicheStringPiece key,
size_t* spdy_header_block_value_size);
SpdyHeaderBlock* block_;
SpdyHeaderBlock::MapType::iterator lookup_result_;
quiche::QuicheStringPiece key_;
size_t* spdy_header_block_value_size_;
bool valid_;
};
// Allows either lookup or mutation of the value associated with a key.
SPDY_MUST_USE_RESULT ValueProxy
operator[](const quiche::QuicheStringPiece key);
// Returns the estimate of dynamically allocated memory in bytes.
size_t EstimateMemoryUsage() const;
size_t TotalBytesUsed() const { return key_size_ + value_size_; }
private:
friend class test::SpdyHeaderBlockPeer;
void AppendHeader(const quiche::QuicheStringPiece key,
const quiche::QuicheStringPiece value);
quiche::QuicheStringPiece WriteKey(const quiche::QuicheStringPiece key);
size_t bytes_allocated() const;
// QuicheStringPieces held by |map_| point to memory owned by |storage_|.
MapType map_;
SpdyHeaderStorage storage_;
size_t key_size_ = 0;
size_t value_size_ = 0;
};
} // namespace spdy
#endif // QUICHE_SPDY_CORE_SPDY_HEADER_BLOCK_H_