Rename offline_profiling_info to profile_compilation_info

This solves a long standing TODO to align the names of the files and the
class.

Bug: 32434870
Test: test-art-host

Change-Id: I2707da8fef8736a7223189d894fc00ff11bfab12
diff --git a/runtime/jit/profile_compilation_info.cc b/runtime/jit/profile_compilation_info.cc
new file mode 100644
index 0000000..1405c40
--- /dev/null
+++ b/runtime/jit/profile_compilation_info.cc
@@ -0,0 +1,715 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "profile_compilation_info.h"
+
+#include "errno.h"
+#include <limits.h>
+#include <vector>
+#include <stdlib.h>
+#include <sys/file.h>
+#include <sys/stat.h>
+#include <sys/uio.h>
+
+#include "art_method-inl.h"
+#include "base/mutex.h"
+#include "base/scoped_flock.h"
+#include "base/stl_util.h"
+#include "base/systrace.h"
+#include "base/unix_file/fd_file.h"
+#include "jit/profiling_info.h"
+#include "os.h"
+#include "safe_map.h"
+
+namespace art {
+
+const uint8_t ProfileCompilationInfo::kProfileMagic[] = { 'p', 'r', 'o', '\0' };
+const uint8_t ProfileCompilationInfo::kProfileVersion[] = { '0', '0', '2', '\0' };
+
+static constexpr uint16_t kMaxDexFileKeyLength = PATH_MAX;
+
+// Debug flag to ignore checksums when testing if a method or a class is present in the profile.
+// Used to facilitate testing profile guided compilation across a large number of apps
+// using the same test profile.
+static constexpr bool kDebugIgnoreChecksum = false;
+
+// Transform the actual dex location into relative paths.
+// Note: this is OK because we don't store profiles of different apps into the same file.
+// Apps with split apks don't cause trouble because each split has a different name and will not
+// collide with other entries.
+std::string ProfileCompilationInfo::GetProfileDexFileKey(const std::string& dex_location) {
+  DCHECK(!dex_location.empty());
+  size_t last_sep_index = dex_location.find_last_of('/');
+  if (last_sep_index == std::string::npos) {
+    return dex_location;
+  } else {
+    DCHECK(last_sep_index < dex_location.size());
+    return dex_location.substr(last_sep_index + 1);
+  }
+}
+
+bool ProfileCompilationInfo::AddMethodsAndClasses(
+    const std::vector<MethodReference>& methods,
+    const std::set<DexCacheResolvedClasses>& resolved_classes) {
+  for (const MethodReference& method : methods) {
+    if (!AddMethodIndex(GetProfileDexFileKey(method.dex_file->GetLocation()),
+                        method.dex_file->GetLocationChecksum(),
+                        method.dex_method_index)) {
+      return false;
+    }
+  }
+  for (const DexCacheResolvedClasses& dex_cache : resolved_classes) {
+    if (!AddResolvedClasses(dex_cache)) {
+      return false;
+    }
+  }
+  return true;
+}
+
+bool ProfileCompilationInfo::MergeAndSave(const std::string& filename,
+                                          uint64_t* bytes_written,
+                                          bool force) {
+  ScopedTrace trace(__PRETTY_FUNCTION__);
+  ScopedFlock flock;
+  std::string error;
+  if (!flock.Init(filename.c_str(), O_RDWR | O_NOFOLLOW | O_CLOEXEC, /* block */ false, &error)) {
+    LOG(WARNING) << "Couldn't lock the profile file " << filename << ": " << error;
+    return false;
+  }
+
+  int fd = flock.GetFile()->Fd();
+
+  // Load the file but keep a copy around to be able to infer if the content has changed.
+  ProfileCompilationInfo fileInfo;
+  ProfileLoadSatus status = fileInfo.LoadInternal(fd, &error);
+  if (status == kProfileLoadSuccess) {
+    // Merge the content of file into the current object.
+    if (MergeWith(fileInfo)) {
+      // If after the merge we have the same data as what is the file there's no point
+      // in actually doing the write. The file will be exactly the same as before.
+      if (Equals(fileInfo)) {
+        if (bytes_written != nullptr) {
+          *bytes_written = 0;
+        }
+        return true;
+      }
+    } else {
+      LOG(WARNING) << "Could not merge previous profile data from file " << filename;
+      if (!force) {
+        return false;
+      }
+    }
+  } else if (force &&
+        ((status == kProfileLoadVersionMismatch) || (status == kProfileLoadBadData))) {
+      // Log a warning but don't return false. We will clear the profile anyway.
+      LOG(WARNING) << "Clearing bad or obsolete profile data from file "
+          << filename << ": " << error;
+  } else {
+    LOG(WARNING) << "Could not load profile data from file " << filename << ": " << error;
+    return false;
+  }
+
+  // We need to clear the data because we don't support appending to the profiles yet.
+  if (!flock.GetFile()->ClearContent()) {
+    PLOG(WARNING) << "Could not clear profile file: " << filename;
+    return false;
+  }
+
+  // This doesn't need locking because we are trying to lock the file for exclusive
+  // access and fail immediately if we can't.
+  bool result = Save(fd);
+  if (result) {
+    VLOG(profiler) << "Successfully saved profile info to " << filename
+        << " Size: " << GetFileSizeBytes(filename);
+    if (bytes_written != nullptr) {
+      *bytes_written = GetFileSizeBytes(filename);
+    }
+  } else {
+    VLOG(profiler) << "Failed to save profile info to " << filename;
+  }
+  return result;
+}
+
+// Returns true if all the bytes were successfully written to the file descriptor.
+static bool WriteBuffer(int fd, const uint8_t* buffer, size_t byte_count) {
+  while (byte_count > 0) {
+    int bytes_written = TEMP_FAILURE_RETRY(write(fd, buffer, byte_count));
+    if (bytes_written == -1) {
+      return false;
+    }
+    byte_count -= bytes_written;  // Reduce the number of remaining bytes.
+    buffer += bytes_written;  // Move the buffer forward.
+  }
+  return true;
+}
+
+// Add the string bytes to the buffer.
+static void AddStringToBuffer(std::vector<uint8_t>* buffer, const std::string& value) {
+  buffer->insert(buffer->end(), value.begin(), value.end());
+}
+
+// Insert each byte, from low to high into the buffer.
+template <typename T>
+static void AddUintToBuffer(std::vector<uint8_t>* buffer, T value) {
+  for (size_t i = 0; i < sizeof(T); i++) {
+    buffer->push_back((value >> (i * kBitsPerByte)) & 0xff);
+  }
+}
+
+static constexpr size_t kLineHeaderSize =
+    3 * sizeof(uint16_t) +  // method_set.size + class_set.size + dex_location.size
+    sizeof(uint32_t);       // checksum
+
+/**
+ * Serialization format:
+ *    magic,version,number_of_lines
+ *    dex_location1,number_of_methods1,number_of_classes1,dex_location_checksum1, \
+ *        method_id11,method_id12...,class_id1,class_id2...
+ *    dex_location2,number_of_methods2,number_of_classes2,dex_location_checksum2, \
+ *        method_id21,method_id22...,,class_id1,class_id2...
+ *    .....
+ **/
+bool ProfileCompilationInfo::Save(int fd) {
+  ScopedTrace trace(__PRETTY_FUNCTION__);
+  DCHECK_GE(fd, 0);
+
+  // Cache at most 5KB before writing.
+  static constexpr size_t kMaxSizeToKeepBeforeWriting = 5 * KB;
+  // Use a vector wrapper to avoid keeping track of offsets when we add elements.
+  std::vector<uint8_t> buffer;
+  WriteBuffer(fd, kProfileMagic, sizeof(kProfileMagic));
+  WriteBuffer(fd, kProfileVersion, sizeof(kProfileVersion));
+  AddUintToBuffer(&buffer, static_cast<uint16_t>(info_.size()));
+
+  for (const auto& it : info_) {
+    if (buffer.size() > kMaxSizeToKeepBeforeWriting) {
+      if (!WriteBuffer(fd, buffer.data(), buffer.size())) {
+        return false;
+      }
+      buffer.clear();
+    }
+    const std::string& dex_location = it.first;
+    const DexFileData& dex_data = it.second;
+    if (dex_data.method_set.empty() && dex_data.class_set.empty()) {
+      continue;
+    }
+
+    if (dex_location.size() >= kMaxDexFileKeyLength) {
+      LOG(WARNING) << "DexFileKey exceeds allocated limit";
+      return false;
+    }
+
+    // Make sure that the buffer has enough capacity to avoid repeated resizings
+    // while we add data.
+    size_t required_capacity = buffer.size() +
+        kLineHeaderSize +
+        dex_location.size() +
+        sizeof(uint16_t) * (dex_data.class_set.size() + dex_data.method_set.size());
+
+    buffer.reserve(required_capacity);
+
+    DCHECK_LE(dex_location.size(), std::numeric_limits<uint16_t>::max());
+    DCHECK_LE(dex_data.method_set.size(), std::numeric_limits<uint16_t>::max());
+    DCHECK_LE(dex_data.class_set.size(), std::numeric_limits<uint16_t>::max());
+    AddUintToBuffer(&buffer, static_cast<uint16_t>(dex_location.size()));
+    AddUintToBuffer(&buffer, static_cast<uint16_t>(dex_data.method_set.size()));
+    AddUintToBuffer(&buffer, static_cast<uint16_t>(dex_data.class_set.size()));
+    AddUintToBuffer(&buffer, dex_data.checksum);  // uint32_t
+
+    AddStringToBuffer(&buffer, dex_location);
+
+    for (auto method_it : dex_data.method_set) {
+      AddUintToBuffer(&buffer, method_it);
+    }
+    for (auto class_id : dex_data.class_set) {
+      AddUintToBuffer(&buffer, class_id.index_);
+    }
+    DCHECK_EQ(required_capacity, buffer.size())
+        << "Failed to add the expected number of bytes in the buffer";
+  }
+
+  return WriteBuffer(fd, buffer.data(), buffer.size());
+}
+
+ProfileCompilationInfo::DexFileData* ProfileCompilationInfo::GetOrAddDexFileData(
+    const std::string& dex_location,
+    uint32_t checksum) {
+  auto info_it = info_.find(dex_location);
+  if (info_it == info_.end()) {
+    info_it = info_.Put(dex_location, DexFileData(checksum));
+  }
+  if (info_it->second.checksum != checksum) {
+    LOG(WARNING) << "Checksum mismatch for dex " << dex_location;
+    return nullptr;
+  }
+  return &info_it->second;
+}
+
+bool ProfileCompilationInfo::AddResolvedClasses(const DexCacheResolvedClasses& classes) {
+  const std::string dex_location = GetProfileDexFileKey(classes.GetDexLocation());
+  const uint32_t checksum = classes.GetLocationChecksum();
+  DexFileData* const data = GetOrAddDexFileData(dex_location, checksum);
+  if (data == nullptr) {
+    return false;
+  }
+  data->class_set.insert(classes.GetClasses().begin(), classes.GetClasses().end());
+  return true;
+}
+
+bool ProfileCompilationInfo::AddMethodIndex(const std::string& dex_location,
+                                            uint32_t checksum,
+                                            uint16_t method_idx) {
+  DexFileData* const data = GetOrAddDexFileData(dex_location, checksum);
+  if (data == nullptr) {
+    return false;
+  }
+  data->method_set.insert(method_idx);
+  return true;
+}
+
+bool ProfileCompilationInfo::AddClassIndex(const std::string& dex_location,
+                                           uint32_t checksum,
+                                           dex::TypeIndex type_idx) {
+  DexFileData* const data = GetOrAddDexFileData(dex_location, checksum);
+  if (data == nullptr) {
+    return false;
+  }
+  data->class_set.insert(type_idx);
+  return true;
+}
+
+bool ProfileCompilationInfo::ProcessLine(SafeBuffer& line_buffer,
+                                         uint16_t method_set_size,
+                                         uint16_t class_set_size,
+                                         uint32_t checksum,
+                                         const std::string& dex_location) {
+  for (uint16_t i = 0; i < method_set_size; i++) {
+    uint16_t method_idx = line_buffer.ReadUintAndAdvance<uint16_t>();
+    if (!AddMethodIndex(dex_location, checksum, method_idx)) {
+      return false;
+    }
+  }
+
+  for (uint16_t i = 0; i < class_set_size; i++) {
+    uint16_t type_idx = line_buffer.ReadUintAndAdvance<uint16_t>();
+    if (!AddClassIndex(dex_location, checksum, dex::TypeIndex(type_idx))) {
+      return false;
+    }
+  }
+  return true;
+}
+
+// Tests for EOF by trying to read 1 byte from the descriptor.
+// Returns:
+//   0 if the descriptor is at the EOF,
+//  -1 if there was an IO error
+//   1 if the descriptor has more content to read
+static int testEOF(int fd) {
+  uint8_t buffer[1];
+  return TEMP_FAILURE_RETRY(read(fd, buffer, 1));
+}
+
+// Reads an uint value previously written with AddUintToBuffer.
+template <typename T>
+T ProfileCompilationInfo::SafeBuffer::ReadUintAndAdvance() {
+  static_assert(std::is_unsigned<T>::value, "Type is not unsigned");
+  CHECK_LE(ptr_current_ + sizeof(T), ptr_end_);
+  T value = 0;
+  for (size_t i = 0; i < sizeof(T); i++) {
+    value += ptr_current_[i] << (i * kBitsPerByte);
+  }
+  ptr_current_ += sizeof(T);
+  return value;
+}
+
+bool ProfileCompilationInfo::SafeBuffer::CompareAndAdvance(const uint8_t* data, size_t data_size) {
+  if (ptr_current_ + data_size > ptr_end_) {
+    return false;
+  }
+  if (memcmp(ptr_current_, data, data_size) == 0) {
+    ptr_current_ += data_size;
+    return true;
+  }
+  return false;
+}
+
+ProfileCompilationInfo::ProfileLoadSatus ProfileCompilationInfo::SafeBuffer::FillFromFd(
+      int fd,
+      const std::string& source,
+      /*out*/std::string* error) {
+  size_t byte_count = ptr_end_ - ptr_current_;
+  uint8_t* buffer = ptr_current_;
+  while (byte_count > 0) {
+    int bytes_read = TEMP_FAILURE_RETRY(read(fd, buffer, byte_count));
+    if (bytes_read == 0) {
+      *error += "Profile EOF reached prematurely for " + source;
+      return kProfileLoadBadData;
+    } else if (bytes_read < 0) {
+      *error += "Profile IO error for " + source + strerror(errno);
+      return kProfileLoadIOError;
+    }
+    byte_count -= bytes_read;
+    buffer += bytes_read;
+  }
+  return kProfileLoadSuccess;
+}
+
+ProfileCompilationInfo::ProfileLoadSatus ProfileCompilationInfo::ReadProfileHeader(
+      int fd,
+      /*out*/uint16_t* number_of_lines,
+      /*out*/std::string* error) {
+  // Read magic and version
+  const size_t kMagicVersionSize =
+    sizeof(kProfileMagic) +
+    sizeof(kProfileVersion) +
+    sizeof(uint16_t);  // number of lines
+
+  SafeBuffer safe_buffer(kMagicVersionSize);
+
+  ProfileLoadSatus status = safe_buffer.FillFromFd(fd, "ReadProfileHeader", error);
+  if (status != kProfileLoadSuccess) {
+    return status;
+  }
+
+  if (!safe_buffer.CompareAndAdvance(kProfileMagic, sizeof(kProfileMagic))) {
+    *error = "Profile missing magic";
+    return kProfileLoadVersionMismatch;
+  }
+  if (!safe_buffer.CompareAndAdvance(kProfileVersion, sizeof(kProfileVersion))) {
+    *error = "Profile version mismatch";
+    return kProfileLoadVersionMismatch;
+  }
+  *number_of_lines = safe_buffer.ReadUintAndAdvance<uint16_t>();
+  return kProfileLoadSuccess;
+}
+
+ProfileCompilationInfo::ProfileLoadSatus ProfileCompilationInfo::ReadProfileLineHeader(
+      int fd,
+      /*out*/ProfileLineHeader* line_header,
+      /*out*/std::string* error) {
+  SafeBuffer header_buffer(kLineHeaderSize);
+  ProfileLoadSatus status = header_buffer.FillFromFd(fd, "ReadProfileHeader", error);
+  if (status != kProfileLoadSuccess) {
+    return status;
+  }
+
+  uint16_t dex_location_size = header_buffer.ReadUintAndAdvance<uint16_t>();
+  line_header->method_set_size = header_buffer.ReadUintAndAdvance<uint16_t>();
+  line_header->class_set_size = header_buffer.ReadUintAndAdvance<uint16_t>();
+  line_header->checksum = header_buffer.ReadUintAndAdvance<uint32_t>();
+
+  if (dex_location_size == 0 || dex_location_size > kMaxDexFileKeyLength) {
+    *error = "DexFileKey has an invalid size: " +
+        std::to_string(static_cast<uint32_t>(dex_location_size));
+    return kProfileLoadBadData;
+  }
+
+  SafeBuffer location_buffer(dex_location_size);
+  status = location_buffer.FillFromFd(fd, "ReadProfileHeaderDexLocation", error);
+  if (status != kProfileLoadSuccess) {
+    return status;
+  }
+  line_header->dex_location.assign(
+      reinterpret_cast<char*>(location_buffer.Get()), dex_location_size);
+  return kProfileLoadSuccess;
+}
+
+ProfileCompilationInfo::ProfileLoadSatus ProfileCompilationInfo::ReadProfileLine(
+      int fd,
+      const ProfileLineHeader& line_header,
+      /*out*/std::string* error) {
+  // Make sure that we don't try to read everything in memory (in case the profile if full).
+  // Split readings in chunks of at most 10kb.
+  static constexpr uint16_t kMaxNumberOfEntriesToRead = 5120;
+  uint16_t methods_left_to_read = line_header.method_set_size;
+  uint16_t classes_left_to_read = line_header.class_set_size;
+
+  while ((methods_left_to_read > 0) || (classes_left_to_read > 0)) {
+    uint16_t methods_to_read = std::min(kMaxNumberOfEntriesToRead, methods_left_to_read);
+    uint16_t max_classes_to_read = kMaxNumberOfEntriesToRead - methods_to_read;
+    uint16_t classes_to_read = std::min(max_classes_to_read, classes_left_to_read);
+
+    size_t line_size = sizeof(uint16_t) * (methods_to_read + classes_to_read);
+    SafeBuffer line_buffer(line_size);
+
+    ProfileLoadSatus status = line_buffer.FillFromFd(fd, "ReadProfileLine", error);
+    if (status != kProfileLoadSuccess) {
+      return status;
+    }
+    if (!ProcessLine(line_buffer,
+                     methods_to_read,
+                     classes_to_read,
+                     line_header.checksum,
+                     line_header.dex_location)) {
+      *error = "Error when reading profile file line";
+      return kProfileLoadBadData;
+    }
+    methods_left_to_read -= methods_to_read;
+    classes_left_to_read -= classes_to_read;
+  }
+  return kProfileLoadSuccess;
+}
+
+bool ProfileCompilationInfo::Load(int fd) {
+  std::string error;
+  ProfileLoadSatus status = LoadInternal(fd, &error);
+
+  if (status == kProfileLoadSuccess) {
+    return true;
+  } else {
+    PLOG(WARNING) << "Error when reading profile " << error;
+    return false;
+  }
+}
+
+ProfileCompilationInfo::ProfileLoadSatus ProfileCompilationInfo::LoadInternal(
+      int fd, std::string* error) {
+  ScopedTrace trace(__PRETTY_FUNCTION__);
+  DCHECK_GE(fd, 0);
+
+  struct stat stat_buffer;
+  if (fstat(fd, &stat_buffer) != 0) {
+    return kProfileLoadIOError;
+  }
+  // We allow empty profile files.
+  // Profiles may be created by ActivityManager or installd before we manage to
+  // process them in the runtime or profman.
+  if (stat_buffer.st_size == 0) {
+    return kProfileLoadSuccess;
+  }
+  // Read profile header: magic + version + number_of_lines.
+  uint16_t number_of_lines;
+  ProfileLoadSatus status = ReadProfileHeader(fd, &number_of_lines, error);
+  if (status != kProfileLoadSuccess) {
+    return status;
+  }
+
+  while (number_of_lines > 0) {
+    ProfileLineHeader line_header;
+    // First, read the line header to get the amount of data we need to read.
+    status = ReadProfileLineHeader(fd, &line_header, error);
+    if (status != kProfileLoadSuccess) {
+      return status;
+    }
+
+    // Now read the actual profile line.
+    status = ReadProfileLine(fd, line_header, error);
+    if (status != kProfileLoadSuccess) {
+      return status;
+    }
+    number_of_lines--;
+  }
+
+  // Check that we read everything and that profiles don't contain junk data.
+  int result = testEOF(fd);
+  if (result == 0) {
+    return kProfileLoadSuccess;
+  } else if (result < 0) {
+    return kProfileLoadIOError;
+  } else {
+    *error = "Unexpected content in the profile file";
+    return kProfileLoadBadData;
+  }
+}
+
+bool ProfileCompilationInfo::MergeWith(const ProfileCompilationInfo& other) {
+  // First verify that all checksums match. This will avoid adding garbage to
+  // the current profile info.
+  // Note that the number of elements should be very small, so this should not
+  // be a performance issue.
+  for (const auto& other_it : other.info_) {
+    auto info_it = info_.find(other_it.first);
+    if ((info_it != info_.end()) && (info_it->second.checksum != other_it.second.checksum)) {
+      LOG(WARNING) << "Checksum mismatch for dex " << other_it.first;
+      return false;
+    }
+  }
+  // All checksums match. Import the data.
+  for (const auto& other_it : other.info_) {
+    const std::string& other_dex_location = other_it.first;
+    const DexFileData& other_dex_data = other_it.second;
+    auto info_it = info_.find(other_dex_location);
+    if (info_it == info_.end()) {
+      info_it = info_.Put(other_dex_location, DexFileData(other_dex_data.checksum));
+    }
+    info_it->second.method_set.insert(other_dex_data.method_set.begin(),
+                                      other_dex_data.method_set.end());
+    info_it->second.class_set.insert(other_dex_data.class_set.begin(),
+                                     other_dex_data.class_set.end());
+  }
+  return true;
+}
+
+static bool ChecksumMatch(const DexFile& dex_file, uint32_t checksum) {
+  return kDebugIgnoreChecksum || dex_file.GetLocationChecksum() == checksum;
+}
+
+bool ProfileCompilationInfo::ContainsMethod(const MethodReference& method_ref) const {
+  auto info_it = info_.find(GetProfileDexFileKey(method_ref.dex_file->GetLocation()));
+  if (info_it != info_.end()) {
+    if (!ChecksumMatch(*method_ref.dex_file, info_it->second.checksum)) {
+      return false;
+    }
+    const std::set<uint16_t>& methods = info_it->second.method_set;
+    return methods.find(method_ref.dex_method_index) != methods.end();
+  }
+  return false;
+}
+
+bool ProfileCompilationInfo::ContainsClass(const DexFile& dex_file, dex::TypeIndex type_idx) const {
+  auto info_it = info_.find(GetProfileDexFileKey(dex_file.GetLocation()));
+  if (info_it != info_.end()) {
+    if (!ChecksumMatch(dex_file, info_it->second.checksum)) {
+      return false;
+    }
+    const std::set<dex::TypeIndex>& classes = info_it->second.class_set;
+    return classes.find(type_idx) != classes.end();
+  }
+  return false;
+}
+
+uint32_t ProfileCompilationInfo::GetNumberOfMethods() const {
+  uint32_t total = 0;
+  for (const auto& it : info_) {
+    total += it.second.method_set.size();
+  }
+  return total;
+}
+
+uint32_t ProfileCompilationInfo::GetNumberOfResolvedClasses() const {
+  uint32_t total = 0;
+  for (const auto& it : info_) {
+    total += it.second.class_set.size();
+  }
+  return total;
+}
+
+std::string ProfileCompilationInfo::DumpInfo(const std::vector<const DexFile*>* dex_files,
+                                             bool print_full_dex_location) const {
+  std::ostringstream os;
+  if (info_.empty()) {
+    return "ProfileInfo: empty";
+  }
+
+  os << "ProfileInfo:";
+
+  const std::string kFirstDexFileKeySubstitute = ":classes.dex";
+  for (const auto& it : info_) {
+    os << "\n";
+    const std::string& location = it.first;
+    const DexFileData& dex_data = it.second;
+    if (print_full_dex_location) {
+      os << location;
+    } else {
+      // Replace the (empty) multidex suffix of the first key with a substitute for easier reading.
+      std::string multidex_suffix = DexFile::GetMultiDexSuffix(location);
+      os << (multidex_suffix.empty() ? kFirstDexFileKeySubstitute : multidex_suffix);
+    }
+    const DexFile* dex_file = nullptr;
+    if (dex_files != nullptr) {
+      for (size_t i = 0; i < dex_files->size(); i++) {
+        if (location == (*dex_files)[i]->GetLocation()) {
+          dex_file = (*dex_files)[i];
+        }
+      }
+    }
+    os << "\n\tmethods: ";
+    for (const auto method_it : dex_data.method_set) {
+      if (dex_file != nullptr) {
+        os << "\n\t\t" << dex_file->PrettyMethod(method_it, true);
+      } else {
+        os << method_it << ",";
+      }
+    }
+    os << "\n\tclasses: ";
+    for (const auto class_it : dex_data.class_set) {
+      if (dex_file != nullptr) {
+        os << "\n\t\t" << dex_file->PrettyType(class_it);
+      } else {
+        os << class_it << ",";
+      }
+    }
+  }
+  return os.str();
+}
+
+bool ProfileCompilationInfo::Equals(const ProfileCompilationInfo& other) {
+  return info_.Equals(other.info_);
+}
+
+std::set<DexCacheResolvedClasses> ProfileCompilationInfo::GetResolvedClasses() const {
+  std::set<DexCacheResolvedClasses> ret;
+  for (auto&& pair : info_) {
+    const std::string& profile_key = pair.first;
+    const DexFileData& data = pair.second;
+    // TODO: Is it OK to use the same location for both base and dex location here?
+    DexCacheResolvedClasses classes(profile_key, profile_key, data.checksum);
+    classes.AddClasses(data.class_set.begin(), data.class_set.end());
+    ret.insert(classes);
+  }
+  return ret;
+}
+
+void ProfileCompilationInfo::ClearResolvedClasses() {
+  for (auto& pair : info_) {
+    pair.second.class_set.clear();
+  }
+}
+
+// Naive implementation to generate a random profile file suitable for testing.
+bool ProfileCompilationInfo::GenerateTestProfile(int fd,
+                                                 uint16_t number_of_dex_files,
+                                                 uint16_t method_ratio,
+                                                 uint16_t class_ratio) {
+  const std::string base_dex_location = "base.apk";
+  ProfileCompilationInfo info;
+  // The limits are defined by the dex specification.
+  uint16_t max_method = std::numeric_limits<uint16_t>::max();
+  uint16_t max_classes = std::numeric_limits<uint16_t>::max();
+  uint16_t number_of_methods = max_method * method_ratio / 100;
+  uint16_t number_of_classes = max_classes * class_ratio / 100;
+
+  srand(MicroTime());
+
+  // Make sure we generate more samples with a low index value.
+  // This makes it more likely to hit valid method/class indices in small apps.
+  const uint16_t kFavorFirstN = 10000;
+  const uint16_t kFavorSplit = 2;
+
+  for (uint16_t i = 0; i < number_of_dex_files; i++) {
+    std::string dex_location = DexFile::GetMultiDexLocation(i, base_dex_location.c_str());
+    std::string profile_key = GetProfileDexFileKey(dex_location);
+
+    for (uint16_t m = 0; m < number_of_methods; m++) {
+      uint16_t method_idx = rand() % max_method;
+      if (m < (number_of_methods / kFavorSplit)) {
+        method_idx %= kFavorFirstN;
+      }
+      info.AddMethodIndex(profile_key, 0, method_idx);
+    }
+
+    for (uint16_t c = 0; c < number_of_classes; c++) {
+      uint16_t type_idx = rand() % max_classes;
+      if (c < (number_of_classes / kFavorSplit)) {
+        type_idx %= kFavorFirstN;
+      }
+      info.AddClassIndex(profile_key, 0, dex::TypeIndex(type_idx));
+    }
+  }
+  return info.Save(fd);
+}
+
+}  // namespace art