我有一个 chrome 打包的应用程序，其中还包含 PNaCl/NaCl C++ 模块，以及 NaCl 模块需要读入的一些数据文件。但是，我无法让它读入文件。
我根据我能找到的所有文档和官方示例以及以下问题的答案进行了设置：如何在 Chrome 应用程序中包含数据文件以供本机客户端模块读取 https://stackoverflow.com/questions/23416939/how-to-include-a-data-file-in-a-chrome-app-for-a-native-client-module-to-read
SDK 附带的 nacl_io 演示可以做到这一点，但它是用 C 语言编写的，而不是 C++ 语言。
我想出了一个简单的例子，我将在下面发布。当您按下页面上的按钮时，NaCl 模块应该加载 test.txt 的第一个字符并显示它。到目前为止，它总是只响应“-100”（我输入的错误值），这意味着它无法打开文件，而不是文件的第一个字符。
任何人都可以建议一些更改，使其能够正常工作并加载文件吗？
为了运行它，至少在 Mac 上，我使用此命令，并将所有文件放在 ./file-test 目录中：
/Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome --load-and-launch-app=./file-test
请注意，如果您尝试使用它，您很可能需要更改 makefile 中的 NACL_SDK_ROOT 路径。
文件测试.cc
#include "ppapi/cpp/instance.h"
#include "ppapi/cpp/module.h"
#include "ppapi/cpp/var.h"
#include "nacl_io/nacl_io.h"
#include "sys/mount.h"
class FileTestInstance : public pp::Instance {
public:
explicit FileTestInstance(PP_Instance instance) : pp::Instance(instance)
{
// initialize nacl file system
nacl_io_init_ppapi(instance, pp::Module::Get()->get_browser_interface());
// mount the http root at /http
mount("", "/http", "httpfs", 0, "");
}
virtual ~FileTestInstance() {}
// Receive message from javascript
virtual void HandleMessage(const pp::Var& var_message) {
// Open and load from the file
int c;
FILE *file;
file = fopen("/http/test.txt", "r");
if (file) {
c = getc(file);
fclose(file);
} else {
c = -100;
}
// Send message to JavaScript
pp::Var var_reply(c);
PostMessage(var_reply);
}
};
class FileTestModule : public pp::Module {
public:
FileTestModule() : pp::Module() {}
virtual ~FileTestModule() {}
virtual pp::Instance* CreateInstance(PP_Instance instance) {
return new FileTestInstance(instance);
}
};
namespace pp {
Module* CreateModule() {
return new FileTestModule();
}
} // namespace pp
索引.html
<!DOCTYPE html>
<html>
<head>
<title>File Test</title>
<script type="text/javascript" src="script.js"></script>
</head>
<body>
<h1>File Test</h1>
<input type="button" id="test" name="test" value="Test" />
<p><b>Output:</b><p>
<div id="output">
</div>
<p>
<div id="listener">
<embed id="file_test" width=0 height=0 src="file_test.nmf" type="application/x-pnacl" />
</div>
</p>
</body>
</html>
脚本.js
// outgoing messages
function postMessage(message) {
var nacl_module = document.getElementById('file_test')
nacl_module.postMessage(message);
}
// incoming messages
function handleMessage(message_event) {
var outputDiv = document.getElementById('output');
outputDiv.textContent = message_event.data;
}
// button action
function buttonClicked() {
postMessage("file");
}
// set up
function init() {
// add listener to nacl module
var listener = document.getElementById('listener');
listener.addEventListener('message', handleMessage, true);
// add action to button
document.getElementById("test").onclick = buttonClicked;
}
window.onload = init;
main.js
/**
* Listens for the app launching then creates the window
*/
chrome.app.runtime.onLaunched.addListener(function() {
// Center window on screen.
var screenWidth = screen.availWidth;
var screenHeight = screen.availHeight;
var width = 600;
var height = 600;
chrome.app.window.create('index.html', {
id: "File-TestID",
bounds: {
width: width,
height: height,
left: Math.round((screenWidth-width)/2),
top: Math.round((screenHeight-height)/2)
}
});
});
文件测试.nmf
{
"program": {
"portable": {
"pnacl-translate": {
"url": "file_test.pexe"
}
}
}
}
Makefile
#
# Get pepper directory for toolchain and includes.
#
# If NACL_SDK_ROOT is not set, then assume where it can be found.
#
THIS_MAKEFILE := $(abspath $(lastword $(MAKEFILE_LIST)))
NACL_SDK_ROOT ?= $(abspath $(dir $(THIS_MAKEFILE))../../nacl_sdk/pepper_33)
# Project Build flags
WARNINGS := -Wno-long-long -Wall -Wswitch-enum -pedantic -Werror
CXXFLAGS := -pthread -std=gnu++98 $(WARNINGS)
#
# Compute tool paths
#
GETOS := python $(NACL_SDK_ROOT)/tools/getos.py
OSHELPERS = python $(NACL_SDK_ROOT)/tools/oshelpers.py
OSNAME := $(shell $(GETOS))
RM := $(OSHELPERS) rm
PNACL_TC_PATH := $(abspath $(NACL_SDK_ROOT)/toolchain/$(OSNAME)_pnacl)
PNACL_CXX := $(PNACL_TC_PATH)/bin/pnacl-clang++
PNACL_FINALIZE := $(PNACL_TC_PATH)/bin/pnacl-finalize
CXXFLAGS := -I$(NACL_SDK_ROOT)/include -I$(NACL_SDK_ROOT)/include/pnacl
LDFLAGS := -L$(NACL_SDK_ROOT)/lib/pnacl/Release -lppapi_cpp -lppapi -lnacl_io
#
# Disable DOS PATH warning when using Cygwin based tools Windows
#
CYGWIN ?= nodosfilewarning
export CYGWIN
# Declare the ALL target first, to make the 'all' target the default build
all: file_test.pexe
clean:
$(RM) file_test.pexe file_test.bc
file_test.bc: file_test.cc
$(PNACL_CXX) -o $@ $< -O2 $(CXXFLAGS) $(LDFLAGS)
file_test.pexe: file_test.bc
$(PNACL_FINALIZE) -o $@ $<
test.txt
AAAA
