Update Surface ID Terminology

cc/surfaces/surface_id.h

 // Copyright 2014 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 CC_SURFACES_SURFACE_ID_H_
 #define CC_SURFACES_SURFACE_ID_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <functional>
 
 #include "base/format_macros.h"
 #include "base/hash.h"
 #include "base/strings/stringprintf.h"
 
 namespace cc {
 
 class SurfaceId {
  public:
-  SurfaceId() : id_namespace_(0), local_id_(0), nonce_(0) {}
+  SurfaceId() : gpu_id_(0), client_id_(0), local_id_(0), nonce_(0) {}
 
-  SurfaceId(const SurfaceId& other)
-      : id_namespace_(other.id_namespace_),
-        local_id_(other.local_id_),
-        nonce_(other.nonce_) {}
+  SurfaceId(const SurfaceId& other) = default;
 
   // A SurfaceId consists of three components: namespace, local Id, and nonce.
-  // An |id_namespace| is a display compositor service allocated ID that
+  // An |client_id| is a display compositor service allocated ID that
   // uniquely identifies a client.
   // A |local_id| is a sequentially allocated ID generated by the display
   // compositor client.
   // A |nonce| is a cryptographically secure random int that makes a SurfaceId
   // unguessable by other clients.
-  SurfaceId(uint32_t id_namespace, uint32_t local_id, uint64_t nonce)
-      : id_namespace_(id_namespace), local_id_(local_id), nonce_(nonce) {}
+  SurfaceId(uint32_t gpu_id,
+            uint32_t client_id,
+            uint32_t local_id,
+            uint64_t nonce)
+      : gpu_id_(gpu_id),
+        client_id_(client_id),
+        local_id_(local_id),
+        nonce_(nonce) {}
 
   bool is_null() const {
-    return id_namespace_ == 0 && nonce_ == 0 && local_id_ == 0;
+    return gpu_id_ == 0 && client_id_ == 0 && nonce_ == 0 && local_id_ == 0;
   }
 
   size_t hash() const {
-    size_t interim = base::HashInts(id_namespace_, local_id_);
-    return base::HashInts(static_cast<uint64_t>(interim), nonce_);
+    size_t first = base::HashInts(gpu_id_, client_id_);
+    size_t second = base::HashInts(static_cast<uint64_t>(local_id_), nonce_);
+    return base::HashInts(first, second);
   }
 
-  uint32_t id_namespace() const { return id_namespace_; }
+  uint32_t gpu_id() const { return gpu_id_; }
+
+  uint32_t client_id() const { return client_id_; }
 
   uint32_t local_id() const { return local_id_; }
 
   uint64_t nonce() const { return nonce_; }
 
   std::string ToString() const {
-    return base::StringPrintf("%d:%d:%" PRIu64, id_namespace_, local_id_,
-                              nonce_);
+    return base::StringPrintf("%d:%d:%d:%" PRIu64, gpu_id_, client_id_,
+                              local_id_, nonce_);
   }
 
   bool operator==(const SurfaceId& other) const {
-    return id_namespace_ == other.id_namespace_ &&
+    return gpu_id_ == other.gpu_id_ && client_id_ == other.client_id_ &&
            local_id_ == other.local_id_ && nonce_ == other.nonce_;
   }
 
   bool operator!=(const SurfaceId& other) const { return !(*this == other); }
 
   bool operator<(const SurfaceId& other) const {
-    return std::tie(id_namespace_, local_id_, nonce_) <
-           std::tie(other.id_namespace_, other.local_id_, other.nonce_);
+    return std::tie(gpu_id_, client_id_, local_id_, nonce_) <
+           std::tie(other.gpu_id_, other.client_id_, other.local_id_,
+                    other.nonce_);
   }
 
  private:
   // See SurfaceIdAllocator::GenerateId.
-  uint32_t id_namespace_;
+  uint32_t gpu_id_;
+  uint32_t client_id_;
   uint32_t local_id_;
   uint64_t nonce_;

[piman, 2016/07/12 20:57:19]

nit: can we order the fields so that it's more compact - e.g. nonce_ at the
beginning?

[Fady Samuel, 2016/07/12 22:45:34]

tsepez@ preferred nonce at the end for readability.

[piman, 2016/07/12 22:47:50]

ok - it doesn't matter any more.

 };
 
 struct SurfaceIdHash {
   size_t operator()(const SurfaceId& key) const { return key.hash(); }
 };
 
 }  // namespace cc
 
 #endif  // CC_SURFACES_SURFACE_ID_H_