net/proxy/proxy_service_v8.h

   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 #ifndef NET_PROXY_PROXY_SERVICE_V8_H_
   6 #define NET_PROXY_PROXY_SERVICE_V8_H_
   7
   8 #include "base/basictypes.h"
   9 #include "net/base/net_export.h"
  10
  11 namespace net {
  12
  13 class DhcpProxyScriptFetcher;
  14 class HostResolver;
  15 class NetLog;
  16 class NetworkDelegate;
  17 class ProxyConfigService;
  18 class ProxyScriptFetcher;
  19 class ProxyService;
  20
  21 // Creates a proxy service that polls |proxy_config_service| to notice when
  22 // the proxy settings change. We take ownership of |proxy_config_service|.
  23 //
  24 // |num_pac_threads| specifies the maximum number of threads to use for
  25 // executing PAC scripts. Threads are created lazily on demand.
  26 // If |0| is specified, then a default number of threads will be selected.
  27 //
  28 // Having more threads avoids stalling proxy resolve requests when the
  29 // PAC script takes a while to run. This is particularly a problem when PAC
  30 // scripts do synchronous DNS resolutions, since that can take on the order
  31 // of seconds.
  32 //
  33 // However, the disadvantages of using more than 1 thread are:
  34 //   (a) can cause compatibility issues for scripts that rely on side effects
  35 //       between runs (such scripts should not be common though).
  36 //   (b) increases the memory used by proxy resolving, as each thread will
  37 //       duplicate its own script context.
  38
  39 // |proxy_script_fetcher| specifies the dependency to use for downloading
  40 // any PAC scripts. The resulting ProxyService will take ownership of it.
  41 //
  42 // |dhcp_proxy_script_fetcher| specifies the dependency to use for attempting
  43 // to retrieve the most appropriate PAC script configured in DHCP. The
  44 // resulting ProxyService will take ownership of it.
  45 //
  46 // |host_resolver| points to the host resolving dependency the PAC script
  47 // should use for any DNS queries. It must remain valid throughout the
  48 // lifetime of the ProxyService.
  49 //
  50 // ##########################################################################
  51 // # See the warnings in net/proxy/proxy_resolver_v8.h describing the
  52 // # multi-threading model. In order for this to be safe to use, *ALL* the
  53 // # other V8's running in the process must use v8::Locker.
  54 // ##########################################################################
  55 NET_EXPORT ProxyService* CreateProxyServiceUsingV8ProxyResolver(
  56     ProxyConfigService* proxy_config_service,
  57     size_t num_pac_threads,
  58     ProxyScriptFetcher* proxy_script_fetcher,
  59     DhcpProxyScriptFetcher* dhcp_proxy_script_fetcher,
  60     HostResolver* host_resolver,
  61     NetLog* net_log,
  62     NetworkDelegate* network_delegate);
  63
  64 }  // namespace net
  65
  66 #endif  // NET_PROXY_PROXY_SERVICE_V8_H_