| // 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 <stdio.h> |
| #include <stdlib.h> |
| #include "ppapi/c/pp_errors.h" |
| #include "ppapi/c/ppb_instance.h" |
| #include "ppapi/cpp/module.h" |
| #include "ppapi/cpp/var.h" |
| |
| #include "geturl_handler.h" |
| |
| namespace { |
| bool IsError(int32_t result) { |
| return ((PP_OK != result) && (PP_OK_COMPLETIONPENDING != result)); |
| } |
| } // namespace |
| |
| GetURLHandler* GetURLHandler::Create(pp::Instance* instance, |
| const std::string& url) { |
| return new GetURLHandler(instance, url); |
| } |
| |
| GetURLHandler::GetURLHandler(pp::Instance* instance, |
| const std::string& url) |
| : instance_(instance), |
| url_(url), |
| url_request_(instance), |
| url_loader_(instance), |
| buffer_(new char[READ_BUFFER_SIZE]), |
| cc_factory_(this) { |
| url_request_.SetURL(url); |
| url_request_.SetMethod("GET"); |
| url_request_.SetRecordDownloadProgress(true); |
| } |
| |
| GetURLHandler::~GetURLHandler() { |
| delete [] buffer_; |
| buffer_ = NULL; |
| } |
| |
| void GetURLHandler::Start() { |
| pp::CompletionCallback cc = |
| cc_factory_.NewCallback(&GetURLHandler::OnOpen); |
| url_loader_.Open(url_request_, cc); |
| } |
| |
| void GetURLHandler::OnOpen(int32_t result) { |
| if (result != PP_OK) { |
| ReportResultAndDie(url_, "pp::URLLoader::Open() failed", false); |
| return; |
| } |
| // Here you would process the headers. A real program would want to at least |
| // check the HTTP code and potentially cancel the request. |
| // pp::URLResponseInfo response = loader_.GetResponseInfo(); |
| |
| // Try to figure out how many bytes of data are going to be downloaded in |
| // order to allocate memory for the response body in advance (this will |
| // reduce heap traffic and also the amount of memory allocated). |
| // It is not a problem if this fails, it just means that the |
| // url_response_body_.insert() call in GetURLHandler::AppendDataBytes() |
| // will allocate the memory later on. |
| int64_t bytes_received = 0; |
| int64_t total_bytes_to_be_received = 0; |
| if (url_loader_.GetDownloadProgress(&bytes_received, |
| &total_bytes_to_be_received)) { |
| if (total_bytes_to_be_received > 0) { |
| url_response_body_.reserve(total_bytes_to_be_received); |
| } |
| } |
| // We will not use the download progress anymore, so just disable it. |
| url_request_.SetRecordDownloadProgress(false); |
| |
| // Start streaming. |
| ReadBody(); |
| } |
| |
| void GetURLHandler::AppendDataBytes(const char* buffer, int32_t num_bytes) { |
| if (num_bytes <= 0) |
| return; |
| // Make sure we don't get a buffer overrun. |
| num_bytes = std::min(READ_BUFFER_SIZE, num_bytes); |
| // Note that we do *not* try to minimally increase the amount of allocated |
| // memory here by calling url_response_body_.reserve(). Doing so causes a |
| // lot of string reallocations that kills performance for large files. |
| url_response_body_.insert(url_response_body_.end(), |
| buffer, |
| buffer + num_bytes); |
| } |
| |
| void GetURLHandler::OnRead(int32_t result) { |
| if (result == PP_OK) { |
| // Streaming the file is complete, delete the read buffer since it is |
| // no longer needed. |
| delete [] buffer_; |
| buffer_ = NULL; |
| ReportResultAndDie(url_, url_response_body_, true); |
| } else if (result > 0) { |
| // The URLLoader just filled "result" number of bytes into our buffer. |
| // Save them and perform another read. |
| AppendDataBytes(buffer_, result); |
| ReadBody(); |
| } else { |
| // A read error occurred. |
| ReportResultAndDie(url_, |
| "pp::URLLoader::ReadResponseBody() result<0", |
| false); |
| } |
| } |
| |
| void GetURLHandler::ReadBody() { |
| // Note that you specifically want an "optional" callback here. This will |
| // allow ReadBody() to return synchronously, ignoring your completion |
| // callback, if data is available. For fast connections and large files, |
| // reading as fast as we can will make a large performance difference |
| // However, in the case of a synchronous return, we need to be sure to run |
| // the callback we created since the loader won't do anything with it. |
| pp::CompletionCallback cc = |
| cc_factory_.NewOptionalCallback(&GetURLHandler::OnRead); |
| int32_t result = PP_OK; |
| do { |
| result = url_loader_.ReadResponseBody(buffer_, READ_BUFFER_SIZE, cc); |
| // Handle streaming data directly. Note that we *don't* want to call |
| // OnRead here, since in the case of result > 0 it will schedule |
| // another call to this function. If the network is very fast, we could |
| // end up with a deeply recursive stack. |
| if (result > 0) { |
| AppendDataBytes(buffer_, result); |
| } |
| } while (result > 0); |
| |
| if (result != PP_OK_COMPLETIONPENDING) { |
| // Either we reached the end of the stream (result == PP_OK) or there was |
| // an error. We want OnRead to get called no matter what to handle |
| // that case, whether the error is synchronous or asynchronous. If the |
| // result code *is* COMPLETIONPENDING, our callback will be called |
| // asynchronously. |
| cc.Run(result); |
| } |
| } |
| |
| void GetURLHandler::ReportResultAndDie(const std::string& fname, |
| const std::string& text, |
| bool success) { |
| ReportResult(fname, text, success); |
| delete this; |
| } |
| |
| void GetURLHandler::ReportResult(const std::string& fname, |
| const std::string& text, |
| bool success) { |
| if (success) |
| printf("GetURLHandler::ReportResult(Ok).\n"); |
| else |
| printf("GetURLHandler::ReportResult(Err). %s\n", text.c_str()); |
| fflush(stdout); |
| if (instance_) { |
| pp::Var var_result(fname + "\n" + text); |
| instance_->PostMessage(var_result); |
| } |
| } |
| |