Moves components/metrics/chromeos to c/m/serialization/.

components/metrics/chromeos/serialization_utils.cc

-// 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 "components/metrics/chromeos/serialization_utils.h"
-
-#include <sys/file.h>
-
-#include <string>
-#include <vector>
-
-#include "base/file_util.h"
-#include "base/files/file_path.h"
-#include "base/files/scoped_file.h"
-#include "base/logging.h"
-#include "base/memory/scoped_ptr.h"
-#include "base/memory/scoped_vector.h"
-#include "base/strings/string_split.h"
-#include "base/strings/string_util.h"
-#include "components/metrics/chromeos/metric_sample.h"
-
-#define READ_WRITE_ALL_FILE_FLAGS \
-  (S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH)
-
-namespace metrics {
-namespace {
-
-// Reads the next message from |file_descriptor| into |message|.
-//
-// |message| will be set to the empty string if no message could be read (EOF)
-// or the message was badly constructed.
-//
-// Returns false if no message can be read from this file anymore (EOF or
-// unrecoverable error).
-bool ReadMessage(int fd, std::string* message) {
-  CHECK(message);
-
-  int result;
-  int32 message_size;
-  // The file containing the metrics do not leave the device so the writer and
-  // the reader will always have the same endianness.
-  result = HANDLE_EINTR(read(fd, &message_size, sizeof(message_size)));
-  if (result < 0) {
-    DPLOG(ERROR) << "reading metrics message header";
-    return false;
-  }
-  if (result == 0) {
-    // This indicates a normal EOF.
-    return false;
-  }
-  if (result < static_cast<int>(sizeof(message_size))) {
-    DLOG(ERROR) << "bad read size " << result << ", expecting "
-                << sizeof(message_size);
-    return false;
-  }
-
-  // kMessageMaxLength applies to the entire message: the 4-byte
-  // length field and the content.
-  if (message_size > metrics::SerializationUtils::kMessageMaxLength) {
-    DLOG(ERROR) << "message too long : " << message_size;
-    if (HANDLE_EINTR(lseek(fd, message_size - 4, SEEK_CUR)) == -1) {
-      DLOG(ERROR) << "error while skipping message. abort";
-      return false;
-    }
-    // Badly formatted message was skipped. Treat the badly formatted sample as
-    // an empty sample.
-    message->clear();
-    return true;
-  }
-
-  message_size -= sizeof(message_size);  // The message size includes itself.
-  char buffer[metrics::SerializationUtils::kMessageMaxLength];
-  if (!base::ReadFromFD(fd, buffer, message_size)) {
-    DPLOG(ERROR) << "reading metrics message body";
-    return false;
-  }
-  *message = std::string(buffer, message_size);
-  return true;
-}
-
-}  // namespace
-
-scoped_ptr<MetricSample> SerializationUtils::ParseSample(
-    const std::string& sample) {
-  if (sample.empty())
-    return scoped_ptr<MetricSample>();
-
-  std::vector<std::string> parts;
-  base::SplitString(sample, '\0', &parts);
-  // We should have two null terminated strings so split should produce
-  // three chunks.
-  if (parts.size() != 3) {
-    DLOG(ERROR) << "splitting message on \\0 produced " << parts.size()
-                << " parts (expected 3)";
-    return scoped_ptr<MetricSample>();
-  }
-  const std::string& name = parts[0];
-  const std::string& value = parts[1];
-
-  if (LowerCaseEqualsASCII(name, "crash")) {
-    return MetricSample::CrashSample(value);
-  } else if (LowerCaseEqualsASCII(name, "histogram")) {
-    return MetricSample::ParseHistogram(value);
-  } else if (LowerCaseEqualsASCII(name, "linearhistogram")) {
-    return MetricSample::ParseLinearHistogram(value);
-  } else if (LowerCaseEqualsASCII(name, "sparsehistogram")) {
-    return MetricSample::ParseSparseHistogram(value);
-  } else if (LowerCaseEqualsASCII(name, "useraction")) {
-    return MetricSample::UserActionSample(value);
-  } else {
-    DLOG(ERROR) << "invalid event type: " << name << ", value: " << value;
-  }
-  return scoped_ptr<MetricSample>();
-}
-
-void SerializationUtils::ReadAndTruncateMetricsFromFile(
-    const std::string& filename,
-    ScopedVector<MetricSample>* metrics) {
-  struct stat stat_buf;
-  int result;
-
-  result = stat(filename.c_str(), &stat_buf);
-  if (result < 0) {
-    if (errno != ENOENT)
-      DPLOG(ERROR) << filename << ": bad metrics file stat";
-
-    // Nothing to collect---try later.
-    return;
-  }
-  if (stat_buf.st_size == 0) {
-    // Also nothing to collect.
-    return;
-  }
-  base::ScopedFD fd(open(filename.c_str(), O_RDWR));
-  if (fd.get() < 0) {
-    DPLOG(ERROR) << filename << ": cannot open";
-    return;
-  }
-  result = flock(fd.get(), LOCK_EX);
-  if (result < 0) {
-    DPLOG(ERROR) << filename << ": cannot lock";
-    return;
-  }
-
-  // This processes all messages in the log. When all messages are
-  // read and processed, or an error occurs, truncate the file to zero size.
-  for (;;) {
-    std::string message;
-
-    if (!ReadMessage(fd.get(), &message))
-      break;
-
-    scoped_ptr<MetricSample> sample = ParseSample(message);
-    if (sample)
-      metrics->push_back(sample.release());
-  }
-
-  result = ftruncate(fd.get(), 0);
-  if (result < 0)
-    DPLOG(ERROR) << "truncate metrics log";
-
-  result = flock(fd.get(), LOCK_UN);
-  if (result < 0)
-    DPLOG(ERROR) << "unlock metrics log";
-}
-
-bool SerializationUtils::WriteMetricToFile(const MetricSample& sample,
-                                           const std::string& filename) {
-  if (!sample.IsValid())
-    return false;
-
-  base::ScopedFD file_descriptor(open(filename.c_str(),
-                                      O_WRONLY | O_APPEND | O_CREAT,
-                                      READ_WRITE_ALL_FILE_FLAGS));
-
-  if (file_descriptor.get() < 0) {
-    DLOG(ERROR) << "error openning the file";
-    return false;
-  }
-
-  fchmod(file_descriptor.get(), READ_WRITE_ALL_FILE_FLAGS);
-  // Grab a lock to avoid chrome truncating the file
-  // underneath us. Keep the file locked as briefly as possible.
-  // Freeing file_descriptor will close the file and and remove the lock.
-  if (HANDLE_EINTR(flock(file_descriptor.get(), LOCK_EX)) < 0) {
-    DLOG(ERROR) << "error locking" << filename << " : " << errno;
-    return false;
-  }
-
-  std::string msg = sample.ToString();
-  int32 size = msg.length() + sizeof(int32);
-  if (size > kMessageMaxLength) {
-    DLOG(ERROR) << "cannot write message: too long";
-    return false;
-  }
-
-  // The file containing the metrics samples will only be read by programs on
-  // the same device so we do not check endianness.
-  if (base::WriteFileDescriptor(file_descriptor.get(),
-                                reinterpret_cast<char*>(&size),
-                                sizeof(size)) != sizeof(size)) {
-    DLOG(ERROR) << "error writing message length " << errno;
-    return false;
-  }
-
-  if (base::WriteFileDescriptor(
-          file_descriptor.get(), msg.c_str(), msg.length()) !=
-      static_cast<int>(msg.length())) {
-    DLOG(ERROR) << "error writing message" << errno;
-    return false;
-  }
-
-  return true;
-}
-
-}  // namespace metrics