Index: chrome/renderer/net/predictor_queue.cc |
diff --git a/chrome/renderer/net/predictor_queue.cc b/chrome/renderer/net/predictor_queue.cc |
deleted file mode 100644 |
index 35023efb4cbb2f63d8d89cc6891a2f188a1f9c78..0000000000000000000000000000000000000000 |
--- a/chrome/renderer/net/predictor_queue.cc |
+++ /dev/null |
@@ -1,152 +0,0 @@ |
-// Copyright (c) 2006-2008 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. |
- |
-// See header file for description of DnsQueue class |
- |
-#include "chrome/renderer/net/predictor_queue.h" |
- |
-#include "base/logging.h" |
-#include "base/metrics/stats_counters.h" |
- |
-DnsQueue::DnsQueue(BufferSize size) |
- : buffer_(new char[size + 2]), |
- buffer_size_(size + 1), |
- buffer_sentinel_(size + 1), |
- size_(0) { |
- CHECK(0 < static_cast<BufferSize>(size + 3)); // Avoid overflow worries. |
- buffer_[buffer_sentinel_] = '\0'; // Guard byte to help reading data. |
- readable_ = writeable_ = 0; // Buffer starts empty. |
-} |
- |
-DnsQueue::~DnsQueue(void) { |
-} |
- |
-void DnsQueue::Clear() { |
- size_ = 0; |
- readable_ = writeable_; |
- DCHECK(Validate()); |
-} |
- |
-// Push takes an unterminated string plus its length. |
-// The string must not contain a null terminator. |
-// Exactly length chars are written, or nothing is written. |
-// Returns true for success, false there was no room to push. |
-DnsQueue::PushResult DnsQueue::Push(const char* source, |
- const size_t unsigned_length) { |
- BufferSize length = static_cast<BufferSize>(unsigned_length); |
- if (0 > length+1) // Avoid overflows in conversion to signed. |
- return OVERFLOW_PUSH; |
- |
- // To save on sites with a LOT of links to the SAME domain, we have a |
- // a compaction hack that removes duplicates when we try to push() a |
- // match with the last push. |
- if (0 < size_ && readable_ + length < buffer_sentinel_ && |
- 0 == strncmp(source, &buffer_[readable_], unsigned_length) && |
- '\0' == buffer_[readable_ + unsigned_length]) { |
- SIMPLE_STATS_COUNTER("DNS.PrefetchDnsRedundantPush"); |
- |
- // We already wrote this name to the queue, so we'll skip this repeat. |
- return REDUNDANT_PUSH; |
- } |
- |
- // Calling convention precludes nulls. |
- DCHECK(!length || '\0' != source[length - 1]); |
- |
- DCHECK(Validate()); |
- |
- BufferSize available_space = readable_ - writeable_; |
- |
- if (0 >= available_space) { |
- available_space += buffer_size_; |
- } |
- |
- if (length + 1 >= available_space) { |
- SIMPLE_STATS_COUNTER("DNS.PrefetchDnsQueueFull"); |
- return OVERFLOW_PUSH; // Not enough space to push. |
- } |
- |
- BufferSize dest = writeable_; |
- BufferSize space_till_wrap = buffer_sentinel_ - dest; |
- if (space_till_wrap < length + 1) { |
- // Copy until we run out of room at end of buffer. |
- std::memcpy(&buffer_[dest], source, space_till_wrap); |
- // Ensure caller didn't have embedded '\0' and also |
- // ensure trailing sentinel was in place. |
- // Relies on sentinel. |
- DCHECK(static_cast<size_t>(space_till_wrap) == strlen(&buffer_[dest])); |
- |
- length -= space_till_wrap; |
- source += space_till_wrap; |
- dest = 0; // Continue writing at start of buffer. |
- } |
- |
- // Copy any remaining portion of source. |
- std::memcpy(&buffer_[dest], source, length); |
- DCHECK(dest + length < buffer_sentinel_); |
- buffer_[dest + length] = '\0'; // We need termination in our buffer. |
- // Preclude embedded '\0'. |
- DCHECK(static_cast<size_t>(length) == strlen(&buffer_[dest])); |
- |
- dest += length + 1; |
- if (dest == buffer_sentinel_) |
- dest = 0; |
- |
- writeable_ = dest; |
- size_++; |
- DCHECK(Validate()); |
- return SUCCESSFUL_PUSH; |
-} |
- |
-// Extracts the next available string from the buffer. |
-// The returned string is null terminated, and hence has length |
-// that is exactly one greater than the written string. |
-// If the buffer is empty, then the Pop and returns false. |
-bool DnsQueue::Pop(std::string* out_string) { |
- DCHECK(Validate()); |
- // Sentinel will preclude memory reads beyond buffer's end. |
- DCHECK('\0' == buffer_[buffer_sentinel_]); |
- |
- if (readable_ == writeable_) { |
- return false; // buffer was empty |
- } |
- |
- // Constructor *may* rely on sentinel for null termination. |
- (*out_string) = &buffer_[readable_]; |
- // Our sentinel_ at end of buffer precludes an overflow in cast. |
- BufferSize first_fragment_size = static_cast<BufferSize> (out_string->size()); |
- |
- BufferSize terminal_null; |
- if (readable_ + first_fragment_size >= buffer_sentinel_) { |
- // Sentinel was used, so we need the portion after the wrap. |
- out_string->append(&buffer_[0]); // Fragment at start of buffer. |
- // Sentinel precludes overflow in cast to signed type. |
- terminal_null = static_cast<BufferSize>(out_string->size()) |
- - first_fragment_size; |
- } else { |
- terminal_null = readable_ + first_fragment_size; |
- } |
- DCHECK('\0' == buffer_[terminal_null]); |
- |
- BufferSize new_readable = terminal_null + 1; |
- if (buffer_sentinel_ == new_readable) |
- new_readable = 0; |
- |
- readable_ = new_readable; |
- size_--; |
- if (readable_ == writeable_ || 0 == size_) { |
- // Queue is empty, so reset to start of buffer to help with peeking. |
- readable_ = writeable_ = 0; |
- } |
- DCHECK(Validate()); |
- return true; |
-} |
- |
-bool DnsQueue::Validate() { |
- return (readable_ >= 0) && |
- readable_ < buffer_sentinel_ && |
- writeable_ >= 0 && |
- writeable_ < buffer_sentinel_ && |
- '\0' == buffer_[buffer_sentinel_] && |
- ((0 == size_) == (readable_ == writeable_)); |
-} |