net/proxy/proxy_resolver_v8.h

   1 // Copyright (c) 2011 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 #ifndef NET_PROXY_PROXY_RESOLVER_V8_H_
   6 #define NET_PROXY_PROXY_RESOLVER_V8_H_
   7
   8 #include "base/compiler_specific.h"
   9 #include "base/memory/scoped_ptr.h"
  10 #include "net/base/net_export.h"
  11 #include "net/proxy/proxy_resolver.h"
  12
  13 namespace gin {
  14 class IsolateHolder;
  15 }  // namespace gin
  16
  17 namespace v8 {
  18 class HeapStatistics;
  19 class Isolate;
  20 }  // namespace v8
  21
  22 namespace net {
  23
  24 // Implementation of ProxyResolver that uses V8 to evaluate PAC scripts.
  25 //
  26 // ----------------------------------------------------------------------------
  27 // !!! Important note on threading model:
  28 // ----------------------------------------------------------------------------
  29 // There can be only one instance of V8 running at a time. To enforce this
  30 // constraint, ProxyResolverV8 holds a v8::Locker during execution. Therefore
  31 // it is OK to run multiple instances of ProxyResolverV8 on different threads,
  32 // since only one will be running inside V8 at a time.
  33 //
  34 // It is important that *ALL* instances of V8 in the process be using
  35 // v8::Locker. If not there can be race conditions between the non-locked V8
  36 // instances and the locked V8 instances used by ProxyResolverV8 (assuming they
  37 // run on different threads).
  38 //
  39 // This is the case with the V8 instance used by chromium's renderer -- it runs
  40 // on a different thread from ProxyResolver (renderer thread vs PAC thread),
  41 // and does not use locking since it expects to be alone.
  42 class NET_EXPORT_PRIVATE ProxyResolverV8 : public ProxyResolver {
  43  public:
  44   // Interface for the javascript bindings.
  45   class NET_EXPORT_PRIVATE JSBindings {
  46    public:
  47     enum ResolveDnsOperation {
  48       DNS_RESOLVE,
  49       DNS_RESOLVE_EX,
  50       MY_IP_ADDRESS,
  51       MY_IP_ADDRESS_EX,
  52     };
  53
  54     JSBindings() {}
  55
  56     // Handler for "dnsResolve()", "dnsResolveEx()", "myIpAddress()",
  57     // "myIpAddressEx()". Returns true on success and fills |*output| with the
  58     // result. If |*terminate| is set to true, then the script execution will
  59     // be aborted. Note that termination may not happen right away.
  60     virtual bool ResolveDns(const std::string& host,
  61                             ResolveDnsOperation op,
  62                             std::string* output,
  63                             bool* terminate) = 0;
  64
  65     // Handler for "alert(message)"
  66     virtual void Alert(const base::string16& message) = 0;
  67
  68     // Handler for when an error is encountered. |line_number| may be -1
  69     // if a line number is not applicable to this error.
  70     virtual void OnError(int line_number, const base::string16& error) = 0;
  71
  72    protected:
  73     virtual ~JSBindings() {}
  74   };
  75
  76   // Constructs a ProxyResolverV8.
  77   ProxyResolverV8();
  78
  79   virtual ~ProxyResolverV8();
  80
  81   JSBindings* js_bindings() const { return js_bindings_; }
  82   void set_js_bindings(JSBindings* js_bindings) { js_bindings_ = js_bindings; }
  83
  84   // ProxyResolver implementation:
  85   virtual int GetProxyForURL(const GURL& url,
  86                              ProxyInfo* results,
  87                              const net::CompletionCallback& /*callback*/,
  88                              RequestHandle* /*request*/,
  89                              const BoundNetLog& net_log) OVERRIDE;
  90   virtual void CancelRequest(RequestHandle request) OVERRIDE;
  91   virtual LoadState GetLoadState(RequestHandle request) const OVERRIDE;
  92   virtual void CancelSetPacScript() OVERRIDE;
  93   virtual int SetPacScript(
  94       const scoped_refptr<ProxyResolverScriptData>& script_data,
  95       const net::CompletionCallback& /*callback*/) OVERRIDE;
  96
  97   // Create an isolate to use for the proxy resolver. If the embedder invokes
  98   // this method multiple times, it must be invoked in a thread safe manner,
  99   // e.g. always from the same thread.
 100   static void EnsureIsolateCreated();
 101
 102   static v8::Isolate* GetDefaultIsolate();
 103
 104   // Get total/ued heap memory usage of all v8 instances used by the proxy
 105   // resolver.
 106   static size_t GetTotalHeapSize();
 107   static size_t GetUsedHeapSize();
 108
 109  private:
 110   static gin::IsolateHolder* g_proxy_resolver_isolate_;
 111
 112   // Context holds the Javascript state for the most recently loaded PAC
 113   // script. It corresponds with the data from the last call to
 114   // SetPacScript().
 115   class Context;
 116
 117   scoped_ptr<Context> context_;
 118
 119   JSBindings* js_bindings_;
 120
 121   DISALLOW_COPY_AND_ASSIGN(ProxyResolverV8);
 122 };
 123
 124 }  // namespace net
 125
 126 #endif  // NET_PROXY_PROXY_RESOLVER_V8_H_