gpu in-memory program cache implementation with a memory limit + lru eviction.

gpu/command_buffer/service/memory_program_cache.cc

+// Copyright (c) 2012 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 "gpu/command_buffer/service/memory_program_cache.h"
+
+#include "base/command_line.h"
+#include "base/metrics/histogram.h"
+#include "base/sha1.h"
+#include "base/string_number_conversions.h"
+#include "gpu/command_buffer/service/gl_utils.h"
+#include "gpu/command_buffer/service/gpu_switches.h"
+#include "ui/gl/gl_bindings.h"
+
+namespace {
+size_t GetCacheSize() {
+  size_t size;
+  const CommandLine* command_line = CommandLine::ForCurrentProcess();
+  if (command_line->HasSwitch(switches::kGpuProgramCacheSizeKb) &&
+      base::StringToSizeT(command_line->GetSwitchValueNative(
+          switches::kGpuProgramCacheSizeKb),
+          &size)) {
+      return size;
+  }
+  return gpu::gles2::MemoryProgramCache::kDefaultMaxProgramCacheMemoryBytes;
+}
+}  // anonymous namespace
+
+namespace gpu {
+namespace gles2 {
+
+MemoryProgramCache::MemoryProgramCache()
+    : max_size_bytes_(GetCacheSize()),
+      curr_size_bytes_(0) { }
+
+MemoryProgramCache::MemoryProgramCache(const size_t max_cache_size_bytes)
+    : max_size_bytes_(max_cache_size_bytes),
+      curr_size_bytes_(0) {}
+
+MemoryProgramCache::~MemoryProgramCache() {}
+
+void MemoryProgramCache::ClearBackend() {
+  curr_size_bytes_ = 0;
+  store_.clear();
+  eviction_helper_.Clear();
+}
+
+ProgramCache::ProgramLoadResult MemoryProgramCache::LoadLinkedProgram(
+    GLuint program,
+    ShaderManager::ShaderInfo* shader_a,
+    ShaderManager::ShaderInfo* shader_b,
+    const LocationMap* bind_attrib_location_map) const {
+  char a_sha[kHashLength];
+  char b_sha[kHashLength];
+  ComputeShaderHash(*shader_a->deferred_compilation_source(), a_sha);
+  ComputeShaderHash(*shader_b->deferred_compilation_source(), b_sha);
+
+  char sha[kHashLength];
+  ComputeProgramHash(a_sha,
+                     b_sha,
+                     bind_attrib_location_map,
+                     sha);
+  const std::string sha_string(sha, kHashLength);
+
+  StoreMap::const_iterator found = store_.find(sha_string);
+  if (found == store_.end()) {
+    return PROGRAM_LOAD_FAILURE;
+  }
+  const scoped_refptr<ProgramCacheValue> value = found->second;
+  glProgramBinary(program,
+                  value->format,
+                  static_cast<const GLvoid*>(value->data.get()),
+                  value->length);
+  GLint success = 0;
+  glGetProgramiv(program, GL_LINK_STATUS, &success);
+  if (success == GL_FALSE) {
+    return PROGRAM_LOAD_FAILURE;
+  }
+  shader_a->set_attrib_map(value->attrib_map_0);
+  shader_a->set_uniform_map(value->uniform_map_0);
+  shader_b->set_attrib_map(value->attrib_map_1);
+  shader_b->set_uniform_map(value->uniform_map_1);
+  return PROGRAM_LOAD_SUCCESS;
+}
+
+void MemoryProgramCache::SaveLinkedProgram(
+    GLuint program,
+    const ShaderManager::ShaderInfo* shader_a,
+    const ShaderManager::ShaderInfo* shader_b,
+    const LocationMap* bind_attrib_location_map) {
+  GLsizei length;
+  GLenum format;
+  GLsizei buffer_length = 0;
+  glGetProgramiv(program, GL_PROGRAM_BINARY_LENGTH_OES, &buffer_length);
+  if (static_cast<unsigned int>(buffer_length) > max_size_bytes_) {
+    return;
+  }
+  scoped_array<char> binary(new char[buffer_length]);
+  glGetProgramBinary(program,
+                     buffer_length,
+                     &length,
+                     &format,
+                     binary.get());
+  if (length == 0) {
+    return;
+  }
+
+  char a_sha[kHashLength];
+  char b_sha[kHashLength];
+  ComputeShaderHash(*shader_a->deferred_compilation_source(), a_sha);
+  ComputeShaderHash(*shader_b->deferred_compilation_source(), b_sha);
+
+  char sha[kHashLength];
+  ComputeProgramHash(a_sha,
+                     b_sha,
+                     bind_attrib_location_map,
+                     sha);
+  const std::string sha_string(sha, sizeof(sha));
+
+  if (store_.find(sha_string) != store_.end()) {
+    return;
+  }
+
+  while (curr_size_bytes_ + length > max_size_bytes_) {
+    DCHECK(!eviction_helper_.IsEmpty());
+    const std::string* program = eviction_helper_.PeekKey();
+    const StoreMap::iterator found = store_.find(*program);
+    const ProgramCacheValue* evicting = found->second.get();
+    curr_size_bytes_ -= evicting->length;
+    Evict(*program, evicting->shader_0_hash, evicting->shader_1_hash);
+    store_.erase(found);
+    eviction_helper_.PopKey();
+  }
+  store_[sha_string] = new ProgramCacheValue(length,
+                                             format,
+                                             binary.release(),
+                                             a_sha,
+                                             shader_a->attrib_map(),
+                                             shader_a->uniform_map(),
+                                             b_sha,
+                                             shader_b->attrib_map(),
+                                             shader_b->uniform_map());
+  curr_size_bytes_ += length;
+  eviction_helper_.KeyUsed(sha_string);
+  LinkedProgramCacheSuccess(sha_string,
+                            std::string(a_sha, kHashLength),
+                            std::string(b_sha, kHashLength));
+}
+
+MemoryProgramCache::ProgramCacheValue::ProgramCacheValue(
+    GLsizei _length,
+    GLenum _format,
+    const char* _data,
+    const char* _shader_0_hash,
+    const ShaderTranslator::VariableMap& _attrib_map_0,
+    const ShaderTranslator::VariableMap& _uniform_map_0,
+    const char* _shader_1_hash,
+    const ShaderTranslator::VariableMap& _attrib_map_1,
+    const ShaderTranslator::VariableMap& _uniform_map_1)
+    : length(_length),
+      format(_format),
+      data(_data),
+      shader_0_hash(_shader_0_hash, kHashLength),
+      attrib_map_0(_attrib_map_0),
+      uniform_map_0(_uniform_map_0),
+      shader_1_hash(_shader_1_hash, kHashLength),
+      attrib_map_1(_attrib_map_1),
+      uniform_map_1(_uniform_map_1) {}
+
+MemoryProgramCache::ProgramCacheValue::~ProgramCacheValue() {}
+
+}  // namespace gles2
+}  // namespace gpu