// Copyright 2015 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/system_memory_stats_recorder.h"

#include "base/metrics/histogram_macros.h"
#include "base/process/process_metrics.h"
#include "build/build_config.h"

namespace metrics {

// Record a size in megabytes, a potential interval from 250MB up to 32 GB.
#define UMA_HISTOGRAM_ALLOCATED_MEGABYTES(name, sample) \
  UMA_HISTOGRAM_CUSTOM_COUNTS(name, sample, 250, 32768, 50)

// Records a statistics |sample| for UMA histogram |name|
// using a linear distribution of buckets.
#define UMA_HISTOGRAM_LINEAR(name, sample, max, buckets)                       \
  STATIC_HISTOGRAM_POINTER_BLOCK(                                              \
      name, Add(sample),                                                       \
      base::LinearHistogram::FactoryGet(                                       \
          name,                                                                \
          1, /* Minimum. The 0 bin for underflow is automatically added. */    \
          max + 1,     /* Ensure bucket size of |maximum| / |bucket_count|. */ \
          buckets + 2, /*  Account for the underflow and overflow bins. */     \
          base::Histogram::kUmaTargetedHistogramFlag))

#define UMA_HISTOGRAM_MEGABYTES_LINEAR(name, sample) \
  UMA_HISTOGRAM_LINEAR(name, sample, 2500, 50)

void RecordMemoryStats(RecordMemoryStatsType type) {
  base::SystemMemoryInfoKB memory;
  if (!base::GetSystemMemoryInfo(&memory))
    return;
#if defined(OS_CHROMEOS)
  // Record graphics GEM object size in a histogram with 50 MB buckets.
  int mem_graphics_gem_mb = 0;
  if (memory.gem_size != -1)
    mem_graphics_gem_mb = memory.gem_size / 1024 / 1024;

  // Record shared memory (used by renderer/GPU buffers).
  int mem_shmem_mb = memory.shmem / 1024;
#endif

  // On Intel, graphics objects are in anonymous pages, but on ARM they are
  // not. For a total "allocated count" add in graphics pages on ARM.
  int mem_allocated_mb = (memory.active_anon + memory.inactive_anon) / 1024;
#if defined(OS_CHROMEOS) && defined(ARCH_CPU_ARM_FAMILY)
  mem_allocated_mb += mem_graphics_gem_mb;
#endif

  int mem_available_mb =
      (memory.active_file + memory.inactive_file + memory.free) / 1024;

  switch (type) {
    case RECORD_MEMORY_STATS_CONTENTS_OOM_KILLED: {
#if defined(OS_CHROMEOS)
      UMA_HISTOGRAM_MEGABYTES_LINEAR("Memory.OOMKill.Contents.MemGraphicsMB",
                                     mem_graphics_gem_mb);
      UMA_HISTOGRAM_MEGABYTES_LINEAR("Memory.OOMKill.Contents.MemShmemMB",
                                     mem_shmem_mb);
#endif
      UMA_HISTOGRAM_ALLOCATED_MEGABYTES(
          "Memory.OOMKill.Contents.MemAllocatedMB", mem_allocated_mb);
      UMA_HISTOGRAM_LARGE_MEMORY_MB("Memory.OOMKill.Contents.MemAvailableMB",
                                    mem_available_mb);
      break;
    }
    case RECORD_MEMORY_STATS_EXTENSIONS_OOM_KILLED: {
#if defined(OS_CHROMEOS)
      UMA_HISTOGRAM_MEGABYTES_LINEAR("Memory.OOMKill.Extensions.MemGraphicsMB",
                                     mem_graphics_gem_mb);
      UMA_HISTOGRAM_MEGABYTES_LINEAR("Memory.OOMKill.Extensions.MemShmemMB",
                                     mem_shmem_mb);
#endif
      UMA_HISTOGRAM_ALLOCATED_MEGABYTES(
          "Memory.OOMKill.Extensions.MemAllocatedMB", mem_allocated_mb);
      UMA_HISTOGRAM_LARGE_MEMORY_MB("Memory.OOMKill.Extensions.MemAvailableMB",
                                    mem_available_mb);
      break;
    }
  }
}

}  // namespace metrics