1 files changed, 134 insertions, 0 deletions
diff --git a/ppapi/proxy/plugin_var_tracker.cc b/ppapi/proxy/plugin_var_tracker.cc
new file mode 100644
index 0000000..b28fc38
--- /dev/null
+++ b/ppapi/proxy/plugin_var_tracker.cc
@@ -0,0 +1,134 @@
+// Copyright (c) 2010 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 "ppapi/proxy/plugin_var_tracker.h"
+
+#include "base/ref_counted.h"
+#include "ppapi/c/ppb_var.h"
+#include "ppapi/proxy/plugin_dispatcher.h"
+#include "ppapi/proxy/ppapi_messages.h"
+
+namespace pp {
+namespace proxy {
+
+namespace {
+
+class RefCountedString : public base::RefCounted<RefCountedString> {
+ public:
+  RefCountedString() {
+  }
+  RefCountedString(const std::string& str) : value_(str) {
+  }
+  RefCountedString(const char* data, size_t len)
+      : value_(data, len) {
+  }
+
+  const std::string& value() const { return value_; }
+
+ private:
+  std::string value_;
+};
+
+// When running in the plugin, this will convert the string ID to the object
+// using casting. No validity checking is done.
+RefCountedString* PluginStringFromID(int64 id) {
+  return reinterpret_cast<RefCountedString*>(static_cast<intptr_t>(id));
+}
+
+}  // namespace
+
+PluginVarTracker::PluginVarTracker(PluginDispatcher* dispatcher)
+    : dispatcher_(dispatcher),
+      browser_var_interface_(NULL) {
+}
+
+void PluginVarTracker::Init() {
+  browser_var_interface_ = reinterpret_cast<const PPB_Var*>(
+      dispatcher_->GetLocalInterface(PPB_VAR_INTERFACE));
+}
+
+int64 PluginVarTracker::MakeString(const std::string& str) {
+  RefCountedString* out = new RefCountedString(str);
+  out->AddRef();
+  return static_cast<int64>(reinterpret_cast<intptr_t>(out));
+}
+
+std::string PluginVarTracker::GetString(const PP_Var& var) const {
+  return PluginStringFromID(var.value.as_id)->value();
+}
+
+const std::string* PluginVarTracker::GetExistingString(
+    const PP_Var& var) const {
+  if (var.type != PP_VARTYPE_STRING)
+    return NULL;
+  RefCountedString* str = PluginStringFromID(var.value.as_id);
+  return &str->value();
+}
+
+void PluginVarTracker::AddRef(const PP_Var& var) {
+  if (var.type == PP_VARTYPE_STRING) {
+    PluginStringFromID(var.value.as_id)->AddRef();
+  } else if (var.type == PP_VARTYPE_OBJECT && var.value.as_id != 0) {
+    int& ref_count = object_ref_count_[var.value.as_id];
+    ref_count++;
+    if (ref_count == 1) {
+      // We must handle the case where we got requested to AddRef an object
+      // that we've never seen before. This should tell the browser we've
+      // taken a ref. This comes up when the browser passes an object as an
+      // input param and holds a ref for us. We may not have seen that object
+      // and the plugin handler may want to AddRef and release it internally.
+      SendAddRefObjectMsg(var.value.as_id);
+    }
+  }
+}
+
+void PluginVarTracker::Release(const PP_Var& var) {
+  if (var.type == PP_VARTYPE_STRING) {
+    PluginStringFromID(var.value.as_id)->Release();
+  } else if (var.type == PP_VARTYPE_OBJECT) {
+    ObjectRefCount::iterator found = object_ref_count_.find(var.value.as_id);
+    if (found == object_ref_count_.end())
+      return;  // Invalid object.
+    found->second--;
+
+    if (found->second == 0) {
+      // Plugin has released all of its refs, tell the browser.
+      object_ref_count_.erase(found);
+      SendReleaseObjectMsg(var.value.as_id);
+    }
+  }
+}
+
+void PluginVarTracker::ReceiveObjectPassRef(const PP_Var& var) {
+  // We're the plugin and the renderer just sent us a ref. The renderer has
+  // addrefed the var in its tracker for us since it's returning it.
+  //
+  // - If We don't have a reference to this already, then we just add it to
+  //   our tracker and use that one ref.
+  //
+  // - If we do already have a reference to it, that means the renderer now
+  //   has two references on our behalf. We want to transfer that extra
+  //   reference to our list. This means we addref in the plugin, and release
+  //   the extra one in the renderer.
+  ObjectRefCount::iterator found = object_ref_count_.find(var.value.as_id);
+  if (found == object_ref_count_.end()) {
+    object_ref_count_[var.value.as_id] = 1;
+  } else {
+    SendReleaseObjectMsg(var.value.as_id);
+    found->second++;
+  }
+}
+
+void PluginVarTracker::SendAddRefObjectMsg(int64_t id) {
+  dispatcher_->Send(new PpapiHostMsg_PPBVar_AddRefObject(
+        INTERFACE_ID_PPB_VAR_DEPRECATED, id));
+}
+
+void PluginVarTracker::SendReleaseObjectMsg(int64_t id) {
+  dispatcher_->Send(new PpapiHostMsg_PPBVar_ReleaseObject(
+        INTERFACE_ID_PPB_VAR_DEPRECATED, id));
+}
+
+}  // namesace proxy
+}  // namespace pp