Support asynchronous continuation of custom scheme handler responses (issue #269).

git-svn-id: https://chromiumembedded.googlecode.com/svn/trunk@278 5089003a-bbd8-11dd-ad1f-f1f9622dbc98

include/cef_capi.h

@@ -2270,7 +2270,36 @@ typedef struct _cef_scheme_handler_factory_t
 
 
 ///
-// Structure used to represent a custom scheme handler structure. The functions
+// Structure used to facilitate asynchronous responses to custom scheme handler
+// requests. The functions of this structure may be called on any thread.
+///
+typedef struct _cef_scheme_handler_callback_t
+{
+  // Base structure.
+  cef_base_t base;
+
+  ///
+  // Notify that header information is now available for retrieval.
+  ///
+  void (CEF_CALLBACK *headers_available)(
+      struct _cef_scheme_handler_callback_t* self);
+
+  ///
+  // Notify that response data is now available for reading.
+  ///
+  void (CEF_CALLBACK *bytes_available)(
+      struct _cef_scheme_handler_callback_t* self);
+
+  ///
+  // Cancel processing of the request.
+  ///
+  void (CEF_CALLBACK *cancel)(struct _cef_scheme_handler_callback_t* self);
+
+} cef_scheme_handler_callback_t;
+
+
+///
+// Structure used to implement a custom scheme handler structure. The functions
 // of this structure will always be called on the IO thread.
 ///
 typedef struct _cef_scheme_handler_t
@@ -2279,35 +2308,44 @@ typedef struct _cef_scheme_handler_t
   cef_base_t base;
 
   ///
-  // Process the request. All response generation should take place in this
-  // function. If there is no response set |response_length| to zero or return
-  // false (0) and read_response() will not be called. If the response length is
-  // not known set |response_length| to -1 and read_response() will be called
-  // until it returns false (0) or until the value of |bytes_read| is set to 0.
-  // If the response length is known set |response_length| to a positive value
-  // and read_response() will be called until it returns false (0), the value of
-  // |bytes_read| is set to 0 or the specified number of bytes have been read.
-  // Use the |response| object to set the mime type, http status code and
-  // optional header values for the response and return true (1). To redirect
-  // the request to a new URL set |redirectUrl| to the new URL and return true
-  // (1).
+  // Begin processing the request. To handle the request return true (1) and
+  // call headers_available() once the response header information is available
+  // (headers_available() can also be called from inside this function if header
+  // information is available immediately). To redirect the request to a new URL
+  // set |redirectUrl| to the new URL and return true (1). To cancel the request
+  // return false (0).
   ///
   int (CEF_CALLBACK *process_request)(struct _cef_scheme_handler_t* self,
       struct _cef_request_t* request, cef_string_t* redirectUrl,
-      struct _cef_response_t* response, int* response_length);
+      struct _cef_scheme_handler_callback_t* callback);
 
   ///
-  // Cancel processing of the request.
+  // Retrieve response header information. If the response length is not known
+  // set |response_length| to -1 and read_response() will be called until it
+  // returns false (0). If the response length is known set |response_length| to
+  // a positive value and read_response() will be called until it returns false
+  // (0) or the specified number of bytes have been read. Use the |response|
+  // object to set the mime type, http status code and other optional header
+  // values.
   ///
-  void (CEF_CALLBACK *cancel)(struct _cef_scheme_handler_t* self);
+  void (CEF_CALLBACK *get_response_headers)(struct _cef_scheme_handler_t* self,
+      struct _cef_response_t* response, int64* response_length);
 
   ///
-  // Copy up to |bytes_to_read| bytes into |data_out|. If the copy succeeds set
-  // |bytes_read| to the number of bytes copied and return true (1). If the copy
-  // fails return false (0) and read_response() will not be called again.
+  // Read response data. If data is available immediately copy up to
+  // |bytes_to_read| bytes into |data_out|, set |bytes_read| to the number of
+  // bytes copied, and return true (1). To read the data at a later time set
+  // |bytes_read| to 0, return true (1) and call bytes_available() when the data
+  // is available. To indicate response completion return false (0).
   ///
   int (CEF_CALLBACK *read_response)(struct _cef_scheme_handler_t* self,
-      void* data_out, int bytes_to_read, int* bytes_read);
+      void* data_out, int bytes_to_read, int* bytes_read,
+      struct _cef_scheme_handler_callback_t* callback);
+
+  ///
+  // Request processing has been canceled.
+  ///
+  void (CEF_CALLBACK *cancel)(struct _cef_scheme_handler_t* self);
 
 } cef_scheme_handler_t;