Android systrace: Optimize memory dumps.

systrace/atrace_helper/jni/process_memory_stats.h

 // Copyright 2017 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 PROCESS_MEMORY_STATS_H_
 #define PROCESS_MEMORY_STATS_H_
 
 #include <stdint.h>
 
-#include <map>
 #include <memory>
+#include <vector>
 
 // Reads process memory stats from /proc/pid/{statm,smaps}.
 class ProcessMemoryStats {
  public:
   struct MmapInfo {
     char mapped_file[128] = {};
     char prot_flags[5] = {};
     uint64_t start_addr = 0;
     uint64_t end_addr = 0;
     uint64_t virt_kb = 0;
     uint64_t pss_kb = 0;  // Proportional Set Size.
     uint64_t rss_kb = 0;  // Resident Set Size.
     uint64_t private_clean_kb = 0;
     uint64_t private_dirty_kb = 0;
     uint64_t shared_clean_kb = 0;
     uint64_t shared_dirty_kb = 0;
     uint64_t swapped_kb = 0;
   };
 
-  explicit ProcessMemoryStats(int pid);
+  ProcessMemoryStats() {}
 
-  bool ReadLightStats();
-  bool ReadFullStats();
-  bool ReadMemtrackStats();
+  bool ReadLightStats(int pid);
+  bool ReadFullStats(int pid);
+  bool ReadGpuStats(int pid);
 
   // Available after ReadLightStats().
   uint64_t virt_kb() const { return virt_kb_; }
   uint64_t rss_kb() const { return rss_kb_; }
 
   // Available after ReadFullStats().
+  bool full_stats_available() const { return full_stats_; }
   uint64_t pss_kb() const { return pss_kb_; }
   uint64_t private_clean_kb() const { return private_clean_kb_; }
   uint64_t private_dirty_kb() const { return private_dirty_kb_; }
   uint64_t shared_clean_kb() const { return shared_clean_kb_; }
   uint64_t shared_dirty_kb() const { return shared_dirty_kb_; }
   uint64_t swapped_kb() const { return swapped_kb_; }
 
   // Available after ReadMemtrackStats().
+  bool gpu_stats_available() const { return gpu_stats_; }
   uint64_t gpu_graphics_kb() const { return gpu_graphics_kb_; }
   uint64_t gpu_graphics_pss_kb() const { return gpu_graphics_pss_kb_; }
   uint64_t gpu_gl_kb() const { return gpu_gl_kb_; }
   uint64_t gpu_gl_pss_kb() const { return gpu_gl_pss_kb_; }
   uint64_t gpu_other_kb() const { return gpu_other_kb_; }
   uint64_t gpu_other_pss_kb() const { return gpu_other_pss_kb_; }
 
+  size_t mmaps_count() const { return mmaps_.size(); }
+  const MmapInfo* mmap(size_t index) const { return mmaps_[index].get(); }
+
  private:
   ProcessMemoryStats(const ProcessMemoryStats&) = delete;
   void operator=(const ProcessMemoryStats&) = delete;
 
-  const int pid_;
-
   // Light stats.
   uint64_t virt_kb_ = 0;
   uint64_t rss_kb_ = 0;
 
   // Full stats.
+  bool full_stats_ = false;
   uint64_t pss_kb_ = 0;
   uint64_t private_clean_kb_ = 0;
   uint64_t private_dirty_kb_ = 0;
   uint64_t shared_clean_kb_ = 0;
   uint64_t shared_dirty_kb_ = 0;
   uint64_t swapped_kb_ = 0;
 
   // Graphics stats.
+  bool gpu_stats_ = false;
   uint64_t gpu_graphics_kb_ = 0;
   uint64_t gpu_graphics_pss_kb_ = 0;
   uint64_t gpu_gl_kb_ = 0;
   uint64_t gpu_gl_pss_kb_ = 0;
   uint64_t gpu_other_kb_ = 0;
   uint64_t gpu_other_pss_kb_ = 0;
 
-  std::map<uintptr_t, std::unique_ptr<MmapInfo>> mmaps_;
+  std::vector<std::unique_ptr<const MmapInfo>> mmaps_;
 };
 
 #endif  // PROCESS_MEMORY_STATS_H_