Implementation of beginning of Declarative Web Request API backend

chrome/browser/extensions/api/declarative_webrequest/webrequest_condition.cc

+// Copyright (c) 2012 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 "chrome/browser/extensions/api/declarative_webrequest/webrequest_condition.h"
+
+#include "base/bind.h"
+#include "base/lazy_instance.h"
+#include "base/logging.h"
+#include "base/stringprintf.h"
+#include "base/values.h"
+#include "chrome/browser/extensions/api/declarative_webrequest/request_stages.h"
+#include "chrome/browser/extensions/api/declarative_webrequest/webrequest_condition_attribute.h"
+#include "net/url_request/url_request.h"
+
+namespace {
+static extensions::URLMatcherConditionSet::ID g_next_id = 0;
+
+// TODO(battre): improve error messaging to give more meaningful messages
+// to the extension developer.
+// Error messages:
+const char kExpectedDictionary[] = "A condition has to be a dictionary.";
+const char kConditionWithoutInstanceType[] = "A condition had no instanceType";
+const char kExpectedOtherConditionType[] = "Expected a condition of type "
+    "experimental.webRequest.RequestMatcher";
+const char kUnknownConditionAttribute[] = "UnKnown condition attribute '%s'";
+const char kConditionExpectedString[] =
+    "Condition '%s' expected a string value";
+
+// String literals from the JavaScript API:
+const char kRequestMatcher[] = "experimental.webRequest.RequestMatcher";
+const char kInstanceType[] = "instanceType";
+
+const char kHostContainsKey[] = "host_contains";
+const char kHostEqualsKey[] = "host_equals";
+const char kHostPrefixKey[] = "host_prefix";
+const char kHostSuffixKey[] = "host_suffix";
+const char kHostSuffixPathPrefixKey[] = "host_suffix_path_prefix";
+const char kPathContainsKey[] = "path_contains";
+const char kPathEqualsKey[] = "path_equals";
+const char kPathPrefixKey[] = "path_prefix";
+const char kPathSuffixKey[] = "path_suffix";
+const char kQueryContainsKey[] = "query_contains";
+const char kQueryEqualsKey[] = "query_equals";
+const char kQueryPrefixKey[] = "query_prefix";
+const char kQuerySuffixKey[] = "query_suffix";
+const char kURLContainsKey[] = "url_contains";
+const char kURLEqualsKey[] = "url_equals";
+const char kURLPrefixKey[] = "url_prefix";
+const char kURLSuffixKey[] = "url_suffix";
+
+// Registry for all factory methods of extensions::URLMatcherConditionFactory
+// that allows translating string literals from the extension API into
+// the corresponding factory method to be called.
+class URLMatcherConditionFactoryMethods {
+ public:
+  URLMatcherConditionFactoryMethods() {
+    typedef extensions::URLMatcherConditionFactory F;
+    factory_methods_[kHostContainsKey] = &F::CreateHostContainsCondition;
+    factory_methods_[kHostEqualsKey] = &F::CreateHostEqualsCondition;
+    factory_methods_[kHostPrefixKey] = &F::CreateHostPrefixCondition;
+    factory_methods_[kHostSuffixKey] = &F::CreateHostSuffixCondition;
+    factory_methods_[kPathContainsKey] = &F::CreatePathContainsCondition;
+    factory_methods_[kPathEqualsKey] = &F::CreatePathEqualsCondition;
+    factory_methods_[kPathPrefixKey] = &F::CreatePathPrefixCondition;
+    factory_methods_[kPathSuffixKey] = &F::CreatePathSuffixCondition;
+    factory_methods_[kQueryContainsKey] = &F::CreateQueryContainsCondition;
+    factory_methods_[kQueryEqualsKey] = &F::CreateQueryEqualsCondition;
+    factory_methods_[kQueryPrefixKey] = &F::CreateQueryPrefixCondition;
+    factory_methods_[kQuerySuffixKey] = &F::CreateQuerySuffixCondition;
+    factory_methods_[kURLContainsKey] = &F::CreateURLContainsCondition;
+    factory_methods_[kURLEqualsKey] = &F::CreateURLEqualsCondition;
+    factory_methods_[kURLPrefixKey] = &F::CreateURLPrefixCondition;
+    factory_methods_[kURLSuffixKey] = &F::CreateURLSuffixCondition;
+  }
+
+  // Returns whether a factory method for the specified |pattern_type| (e.g.
+  // "host_suffix") is known.
+  bool Contains(const std::string& pattern_type) const {
+    return factory_methods_.find(pattern_type) != factory_methods_.end();
+  }
+
+  // Creates a URLMatcherCondition instance from |url_matcher_condition_factory|
+  // of the given |pattern_type| (e.g. "host_suffix") for the given
+  // |pattern_value| (e.g. "example.com").
+  // The |pattern_type| needs to be known to this class (see Contains()) or
+  // a CHECK is triggered.
+  extensions::URLMatcherCondition Call(
+      extensions::URLMatcherConditionFactory* url_matcher_condition_factory,
+      const std::string& pattern_type,
+      const std::string& pattern_value) const {
+    FactoryMethods::const_iterator i = factory_methods_.find(pattern_type);
+    CHECK(i != factory_methods_.end());
+    const FactoryMethod& method = i->second;
+    return base::Bind(method,
+        base::Unretained(url_matcher_condition_factory)).Run(pattern_value);

[Matt Perry, 2012/03/26 20:21:20]

You don't need to use Bind to invoke here. The syntax for method pointer
invocation is:
 (url_matcher_condition_factory->*method)(pattern_value);

[battre, 2012/03/26 20:38:10]

Done.

+  }
+
+ private:
+  typedef extensions::URLMatcherCondition
+      (extensions::URLMatcherConditionFactory::* FactoryMethod)
+      (const std::string& prefix);
+  typedef std::map<std::string, FactoryMethod> FactoryMethods;
+
+  FactoryMethods factory_methods_;
+
+  DISALLOW_COPY_AND_ASSIGN(URLMatcherConditionFactoryMethods);
+};
+
+static base::LazyInstance<URLMatcherConditionFactoryMethods>
+    g_url_matcher_condition_factory_methods = LAZY_INSTANCE_INITIALIZER;
+
+}  // namespace
+
+namespace extensions {
+
+//
+// WebRequestCondition
+//
+
+WebRequestCondition::WebRequestCondition(
+    const URLMatcherConditionSet& url_matcher_conditions,
+    const WebRequestConditionAttributes& condition_attributes)
+    : url_matcher_conditions_(url_matcher_conditions),
+      condition_attributes_(condition_attributes) {}
+
+WebRequestCondition::~WebRequestCondition() {}
+
+bool WebRequestCondition::IsFulfilled(net::URLRequest* request) const {
+  // All condition attributes must be fulfilled for a fulfilled condition.
+  for (WebRequestConditionAttributes::const_iterator i =
+       condition_attributes_.begin(); i != condition_attributes_.end(); ++i) {
+    if (!(*i)->IsFulfilled(request))
+      return false;
+  }
+  return true;
+}
+
+// static
+scoped_ptr<WebRequestCondition> WebRequestCondition::Create(
+    URLMatcherConditionFactory* url_matcher_condition_factory,
+    const base::Value& condition,
+    std::string* error) {
+  const base::DictionaryValue* condition_dict = NULL;
+  if (!condition.GetAsDictionary(&condition_dict)) {
+    *error = kExpectedDictionary;
+    return scoped_ptr<WebRequestCondition>(NULL);
+  }
+
+  // Verify that we are dealing with a Condition whose type we understand.
+  std::string instance_type;
+  if (!condition_dict->GetString(kInstanceType, &instance_type)) {
+    *error = kConditionWithoutInstanceType;
+    return scoped_ptr<WebRequestCondition>(NULL);
+  }
+  if (instance_type != kRequestMatcher) {
+    *error = kExpectedOtherConditionType;
+    return scoped_ptr<WebRequestCondition>(NULL);
+  }
+
+  WebRequestConditionAttributes attributes;
+  URLMatcherConditionSet::Conditions url_matcher_conditions;
+
+  for (base::DictionaryValue::Iterator iter(*condition_dict);
+       iter.HasNext(); iter.Advance()) {
+    const std::string& condition_attribute_name = iter.key();
+    const Value& condition_attribute_value = iter.value();
+    if (condition_attribute_name == kInstanceType) {
+      // Skip this.
+    } else if (IsURLMatcherConditionAttribute(condition_attribute_name)) {
+      URLMatcherCondition url_matcher_condition =
+          CreateURLMatcherCondition(
+              url_matcher_condition_factory,
+              condition_attribute_name,
+              &condition_attribute_value,
+              error);
+      if (!error->empty())
+        return scoped_ptr<WebRequestCondition>(NULL);
+      url_matcher_conditions.insert(url_matcher_condition);
+    } else if (WebRequestConditionAttribute::IsKnownType(
+        condition_attribute_name)) {
+      scoped_ptr<WebRequestConditionAttribute> attribute =
+          WebRequestConditionAttribute::Create(
+              condition_attribute_name,
+              &condition_attribute_value,
+              error);
+      if (!error->empty())
+        return scoped_ptr<WebRequestCondition>(NULL);
+      attributes.push_back(make_linked_ptr(attribute.release()));
+    } else {
+      *error = base::StringPrintf(kUnknownConditionAttribute,
+                                  condition_attribute_name.c_str());
+      return scoped_ptr<WebRequestCondition>(NULL);
+    }
+  }
+
+  // As the URL is the preliminary matching criterion that triggers the tests
+  // for the remaining condition attributes, we insert an empty URL match if
+  // no other url match conditions were specified. Such an empty URL is always
+  // matched.
+  if (url_matcher_conditions.empty()) {
+    url_matcher_conditions.insert(
+        url_matcher_condition_factory->CreateHostPrefixCondition(""));
+  }
+
+  URLMatcherConditionSet url_matcher_condition_set(++g_next_id,
+                                                   url_matcher_conditions);
+  return scoped_ptr<WebRequestCondition>(
+      new WebRequestCondition(url_matcher_condition_set, attributes));
+}
+
+// static
+bool WebRequestCondition::IsURLMatcherConditionAttribute(
+    const std::string& condition_attribute_name) {
+  return g_url_matcher_condition_factory_methods.Get().Contains(
+      condition_attribute_name);
+}
+
+// static
+URLMatcherCondition WebRequestCondition::CreateURLMatcherCondition(
+    URLMatcherConditionFactory* url_matcher_condition_factory,
+    const std::string& condition_attribute_name,
+    const base::Value* value,
+    std::string* error) {
+  std::string str_value;
+  if (!value->GetAsString(&str_value)) {
+    *error = base::StringPrintf(kConditionExpectedString,
+                                condition_attribute_name.c_str());
+    return URLMatcherCondition();
+  }
+  return g_url_matcher_condition_factory_methods.Get().Call(
+      url_matcher_condition_factory, condition_attribute_name, str_value);
+}
+
+
+//
+// WebRequestConditionCollection
+//
+
+WebRequestConditionCollection::WebRequestConditionCollection(
+    const std::vector<linked_ptr<WebRequestCondition> >& conditions)
+    : conditions_(conditions) {
+  for (Collection::iterator i = conditions_.begin(); i != conditions_.end();
+       ++i) {
+    URLMatcherConditionSet::ID trigger_id =
+        (*i)->url_matcher_condition_set_id();
+    match_triggers_[trigger_id] = i->get();
+  }
+}
+
+WebRequestConditionCollection::~WebRequestConditionCollection() {}
+
+bool WebRequestConditionCollection::IsFulfilled(
+    URLMatcherConditionSet::ID url_match,
+    net::URLRequest* request) const {
+  MatchTriggers::const_iterator trigger = match_triggers_.find(url_match);
+  if (trigger == match_triggers_.end())

[Matt Perry, 2012/03/26 20:21:20]

Should this be an error (DCHECK)? The caller knows that url_match triggered this
collection, which should imply the collection contains a condition that matches.

[battre, 2012/03/26 20:38:10]

Done.

+    return false;
+  DCHECK_EQ(url_match, trigger->second->url_matcher_condition_set_id());
+  if (trigger->second->IsFulfilled(request))

[Matt Perry, 2012/03/26 20:21:20]

nit: return trigger->second->IsFulfilled(request)

[battre, 2012/03/26 20:38:10]

Done.

+    return true;
+  return false;
+}
+
+void WebRequestConditionCollection::AppendURLMatcherConditionSets(
+    std::vector<URLMatcherConditionSet>* condition_sets) const {
+  for (Collection::const_iterator i = conditions_.begin();
+       i != conditions_.end(); ++i) {
+    condition_sets->push_back((*i)->url_matcher_condition_set());
+  }
+}
+
+// static
+scoped_ptr<WebRequestConditionCollection>
+WebRequestConditionCollection::Create(
+    URLMatcherConditionFactory* url_matcher_condition_factory,
+    const AnyVector& conditions,
+    std::string* error) {
+  std::vector<linked_ptr<WebRequestCondition> > result;
+
+  for (AnyVector::const_iterator i = conditions.begin();
+       i != conditions.end(); ++i) {
+    CHECK(i->get());
+    scoped_ptr<WebRequestCondition> condition =
+        WebRequestCondition::Create(url_matcher_condition_factory,
+                                    (*i)->value(), error);
+    if (!error->empty())
+      return scoped_ptr<WebRequestConditionCollection>(NULL);
+    result.push_back(make_linked_ptr(condition.release()));
+  }
+
+  return scoped_ptr<WebRequestConditionCollection>(
+      new WebRequestConditionCollection(result));
+}
+
+}  // namespace extensions