src/gpu/command_buffer/service/mailbox_manager.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "gpu/command_buffer/service/mailbox_manager.h"
   6
   7 #include <algorithm>
   8
   9 #include "base/rand_util.h"
  10 #include "crypto/hmac.h"
  11 #include "gpu/command_buffer/service/texture_manager.h"
  12
  13 namespace gpu {
  14 namespace gles2 {
  15
  16 MailboxName::MailboxName() {
  17   std::fill(key, key + sizeof(key), 0);
  18   std::fill(signature, signature + sizeof(signature), 0);
  19 }
  20
  21 MailboxManager::MailboxManager()
  22     : hmac_(crypto::HMAC::SHA256),
  23       mailbox_to_textures_(std::ptr_fun(&MailboxManager::TargetNameLess)) {
  24   base::RandBytes(private_key_, sizeof(private_key_));
  25   bool success = hmac_.Init(
  26       base::StringPiece(private_key_, sizeof(private_key_)));
  27   DCHECK(success);
  28   DCHECK(!IsMailboxNameValid(MailboxName()));
  29 }
  30
  31 MailboxManager::~MailboxManager() {
  32   DCHECK(mailbox_to_textures_.empty());
  33   DCHECK(textures_to_mailboxes_.empty());
  34 }
  35
  36 void MailboxManager::GenerateMailboxName(MailboxName* name) {
  37   base::RandBytes(name->key, sizeof(name->key));
  38   SignMailboxName(name);
  39 }
  40
  41 Texture* MailboxManager::ConsumeTexture(unsigned target,
  42                                         const MailboxName& name) {
  43   MailboxToTextureMap::iterator it =
  44       mailbox_to_textures_.find(TargetName(target, name));
  45   if (it == mailbox_to_textures_.end())
  46     return NULL;
  47
  48   DCHECK(IsMailboxNameValid(name));
  49   return it->second->first;
  50 }
  51
  52 bool MailboxManager::ProduceTexture(unsigned target,
  53                                     const MailboxName& name,
  54                                     Texture* texture) {
  55   if (!IsMailboxNameValid(name))
  56     return false;
  57
  58   texture->SetMailboxManager(this);
  59   TargetName target_name(target, name);
  60   MailboxToTextureMap::iterator it = mailbox_to_textures_.find(target_name);
  61   if (it != mailbox_to_textures_.end()) {
  62     TextureToMailboxMap::iterator texture_it = it->second;
  63     mailbox_to_textures_.erase(it);
  64     textures_to_mailboxes_.erase(texture_it);
  65   }
  66   TextureToMailboxMap::iterator texture_it =
  67       textures_to_mailboxes_.insert(std::make_pair(texture, target_name));
  68   mailbox_to_textures_.insert(std::make_pair(target_name, texture_it));
  69   DCHECK_EQ(mailbox_to_textures_.size(), textures_to_mailboxes_.size());
  70
  71   return true;
  72 }
  73
  74 void MailboxManager::TextureDeleted(Texture* texture) {
  75   std::pair<TextureToMailboxMap::iterator,
  76             TextureToMailboxMap::iterator> range =
  77       textures_to_mailboxes_.equal_range(texture);
  78   for (TextureToMailboxMap::iterator it = range.first;
  79        it != range.second; ++it) {
  80     size_t count = mailbox_to_textures_.erase(it->second);
  81     DCHECK(count == 1);
  82   }
  83   textures_to_mailboxes_.erase(range.first, range.second);
  84   DCHECK_EQ(mailbox_to_textures_.size(), textures_to_mailboxes_.size());
  85 }
  86
  87 void MailboxManager::SignMailboxName(MailboxName* name) {
  88   bool success = hmac_.Sign(
  89       base::StringPiece(reinterpret_cast<char*>(name->key), sizeof(name->key)),
  90       reinterpret_cast<unsigned char*>(name->signature),
  91       sizeof(name->signature));
  92   DCHECK(success);
  93 }
  94
  95 bool MailboxManager::IsMailboxNameValid(const MailboxName& name) {
  96   return hmac_.Verify(
  97       base::StringPiece(reinterpret_cast<const char*>(name.key),
  98           sizeof(name.key)),
  99       base::StringPiece(reinterpret_cast<const char*>(name.signature),
 100           sizeof(name.signature)));
 101 }
 102
 103 MailboxManager::TargetName::TargetName(unsigned target, const MailboxName& name)
 104     : target(target),
 105       name(name) {
 106 }
 107
 108 bool MailboxManager::TargetNameLess(const MailboxManager::TargetName& lhs,
 109                                     const MailboxManager::TargetName& rhs) {
 110   return memcmp(&lhs, &rhs, sizeof(lhs)) < 0;
 111 }
 112
 113 }  // namespace gles2
 114 }  // namespace gpu