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Unified Diff: mojo/shell/data_pipe_peek.cc

Issue 775343004: Move //mojo/shell to //shell (Closed) Base URL: git@github.com:domokit/mojo.git@master
Patch Set: Created 6 years ago
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Index: mojo/shell/data_pipe_peek.cc
diff --git a/mojo/shell/data_pipe_peek.cc b/mojo/shell/data_pipe_peek.cc
deleted file mode 100644
index c6b041b4bb5cb8c1be118caed403ffb4ed6214a8..0000000000000000000000000000000000000000
--- a/mojo/shell/data_pipe_peek.cc
+++ /dev/null
@@ -1,152 +0,0 @@
-// Copyright 2014 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.
-
-#include "mojo/shell/data_pipe_peek.h"
-
-#include "base/bind.h"
-
-namespace mojo {
-namespace shell {
-
-namespace {
-
-// Sleep for as long as max_sleep_micros if the deadline hasn't been reached
-// and the number of bytes read is still increasing. Returns true if sleep
-// was actually called.
-//
-// This class is a substitute for being able to wait until N bytes are available
-// from a data pipe. The MaybeSleep method is called when num_bytes_read are
-// available but more are needed by the Peek operation. If a second
-// Peek operation finds the same number of bytes after sleeping we assume
-// that there's no point in trying again.
-// TODO(hansmuller): this heuristic is weak. crbug.com/429377
-class PeekSleeper {
- public:
- explicit PeekSleeper(MojoTimeTicks deadline)
- : deadline_(deadline),
- kMaxSleepMicros_(1000 * 10), // 10ms
- last_number_bytes_read_(0) {
- }
-
- bool MaybeSleep(uint32 num_bytes_read) {
- if (num_bytes_read > 0 && last_number_bytes_read_ >= num_bytes_read)
- return false;
- last_number_bytes_read_ = num_bytes_read;
-
- MojoTimeTicks now(GetTimeTicksNow());
- if (now > deadline_)
- return false;
-
- MojoTimeTicks sleep_time = (deadline_ == 0)
- ? kMaxSleepMicros_
- : std::min<int64>(deadline_ - now, PeekSleeper::kMaxSleepMicros_);
- base::PlatformThread::Sleep(base::TimeDelta::FromMicroseconds(sleep_time));
- return true;
- }
-
- private:
- const MojoTimeTicks deadline_; // 0 => MOJO_DEADLINE_INDEFINITE
- const MojoTimeTicks kMaxSleepMicros_;
- uint32 last_number_bytes_read_;
-
- MOJO_DISALLOW_COPY_AND_ASSIGN(PeekSleeper);
-};
-
-enum PeekStatus { kSuccess, kFail, kKeepReading };
-typedef const base::Callback<PeekStatus(const void*, uint32_t, std::string*)>&
- PeekFunc;
-
-// When data is available on source, call peek_func and then either return true
-// and value, continue waiting for enough data to satisfy peek_func, or fail
-// and return false. Fail if the timeout is exceeded.
-// This function is not guaranteed to work correctly if applied to a data pipe
-// that's already been read from.
-bool BlockingPeekHelper(DataPipeConsumerHandle source,
- std::string* value,
- MojoDeadline timeout,
- PeekFunc peek_func) {
- DCHECK(value);
- value->clear();
-
- MojoTimeTicks deadline = (timeout == MOJO_DEADLINE_INDEFINITE) ? 0
- : 1 + GetTimeTicksNow() + static_cast<MojoTimeTicks>(timeout);
- PeekSleeper sleeper(deadline);
-
- MojoResult result;
- do {
- const void* buffer;
- uint32_t num_bytes;
- result =
- BeginReadDataRaw(source, &buffer, &num_bytes, MOJO_READ_DATA_FLAG_NONE);
-
- if (result == MOJO_RESULT_OK) {
- PeekStatus status = peek_func.Run(buffer, num_bytes, value);
- CHECK_EQ(EndReadDataRaw(source, 0), MOJO_RESULT_OK);
- switch (status) {
- case PeekStatus::kSuccess: return true;
- case PeekStatus::kFail: return false;
- case PeekStatus::kKeepReading: break;
- }
- if (!sleeper.MaybeSleep(num_bytes))
- return false;
- } else if (result == MOJO_RESULT_SHOULD_WAIT) {
- MojoTimeTicks now(GetTimeTicksNow());
- if (timeout == MOJO_DEADLINE_INDEFINITE || now < deadline)
- result = Wait(source, MOJO_HANDLE_SIGNAL_READABLE, deadline - now);
- }
- }
- while(result == MOJO_RESULT_OK);
-
- return false;
-}
-
-PeekStatus PeekLine(size_t max_line_length,
- const void* buffer,
- uint32 buffer_num_bytes,
- std::string* line) {
- const char* p = static_cast<const char*>(buffer);
- size_t max_p_index = std::min<size_t>(buffer_num_bytes, max_line_length);
- for (size_t i = 0; i < max_p_index; i++) {
- if (p[i] == '\n') {
- *line = std::string(p, i + 1); // Include the trailing newline.
- return PeekStatus::kSuccess;
- }
- }
- return (buffer_num_bytes >= max_line_length)
- ? PeekStatus::kFail : PeekStatus::kKeepReading;
-}
-
-PeekStatus PeekNBytes(size_t bytes_length,
- const void* buffer,
- uint32 buffer_num_bytes,
- std::string* bytes) {
- if (buffer_num_bytes >= bytes_length) {
- const char* p = static_cast<const char*>(buffer);
- *bytes = std::string(p, bytes_length);
- return PeekStatus::kSuccess;
- }
- return PeekStatus::kKeepReading;
-}
-
-} // namespace
-
-
-bool BlockingPeekNBytes(DataPipeConsumerHandle source,
- std::string* bytes,
- size_t bytes_length,
- MojoDeadline timeout) {
- PeekFunc peek_nbytes = base::Bind(PeekNBytes, bytes_length);
- return BlockingPeekHelper(source, bytes, timeout, peek_nbytes);
-}
-
-bool BlockingPeekLine(DataPipeConsumerHandle source,
- std::string* line,
- size_t max_line_length,
- MojoDeadline timeout) {
- PeekFunc peek_line = base::Bind(PeekLine, max_line_length);
- return BlockingPeekHelper(source, line, timeout, peek_line);
-}
-
-} // namespace shell
-} // namespace mojo
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