NS_IMETHODIMP
nsMsgSaveAsListener::OnStopRequest(nsIRequest *request, nsISupports * aCtxt, nsresult aStatus)
{
if (m_outputStream)
{
m_outputStream->Flush();
m_outputStream->Close();
}
return NS_OK;
}
NS_IMETHODIMP
ServeResourceEvent::Run() {
bool more = false; // Are there HTTP headers to read after the first line
nsCString line; // Contains the current line read from input stream
nsLineBuffer<char>* buffer = new nsLineBuffer<char>();
nsresult rv = ReadCRLF(mInput.get(), buffer, line, &more);
if (NS_FAILED(rv)) { Shutdown(); return rv; }
// First line contains the HTTP GET request. Extract the URL and obtain
// the MediaResource for it.
nsRefPtr<MediaResource> resource = GetMediaResource(line);
if (!resource) {
const char* response_404 = "HTTP/1.1 404 Not Found\r\n"
"Content-Length: 0\r\n\r\n";
rv = WriteAll(response_404, strlen(response_404));
Shutdown();
return rv;
}
// Offset in bytes to start reading from resource.
// This is zero by default but can be set to another starting value if
// this HTTP request includes a byte range request header.
int64_t start = 0;
// Keep reading lines until we get a zero length line, which is the HTTP
// protocol's way of signifying the end of headers and start of body, or
// until we have no more data to read.
while (more && line.Length() > 0) {
rv = ReadCRLF(mInput.get(), buffer, line, &more);
if (NS_FAILED(rv)) { Shutdown(); return rv; }
// Look for a byte range request header. If there is one, set the
// media resource offset to start from to that requested. Here we
// only check for the range request format used by Android rather
// than implementing all possibilities in the HTTP specification.
// That is, the range request is of the form:
// Range: bytes=nnnn-
// Were 'nnnn' is an integer number.
// The end of the range is not checked, instead we return up to
// the end of the resource and the client is informed of this via
// the content-range header.
NS_NAMED_LITERAL_CSTRING(byteRange, "Range: bytes=");
const char* s = strstr(line.get(), byteRange.get());
if (s) {
start = strtoll(s+byteRange.Length(), nullptr, 10);
// Clamp 'start' to be between 0 and the resource length.
start = std::max(int64_t(0), std::min(resource->GetLength(), start));
}
}
// HTTP response to use if this is a non byte range request
const char* response_normal = "HTTP/1.1 200 OK\r\n";
// HTTP response to use if this is a byte range request
const char* response_range = "HTTP/1.1 206 Partial Content\r\n";
// End of HTTP reponse headers is indicated by an empty line.
const char* response_end = "\r\n";
// If the request was a byte range request, we need to read from the
// requested offset. If the resource is non-seekable, or the seek
// fails, then the start offset is set back to zero. This results in all
// HTTP response data being as if the byte range request was not made.
if (start > 0 && !resource->IsTransportSeekable()) {
start = 0;
}
const char* response_line = start > 0 ?
response_range :
response_normal;
rv = WriteAll(response_line, strlen(response_line));
if (NS_FAILED(rv)) { Shutdown(); return NS_OK; }
// Buffer used for reading from the input stream and writing to
// the output stream. The buffer size should be big enough for the
// HTTP response headers sent below. A static_assert ensures
// this where the buffer is used.
const int buffer_size = 32768;
nsAutoArrayPtr<char> b(new char[buffer_size]);
// If we know the length of the resource, send a Content-Length header.
int64_t contentlength = resource->GetLength() - start;
if (contentlength > 0) {
static_assert (buffer_size > 1024,
"buffer_size must be large enough "
"to hold response headers");
snprintf(b, buffer_size, "Content-Length: %" PRId64 "\r\n", contentlength);
rv = WriteAll(b, strlen(b));
if (NS_FAILED(rv)) { Shutdown(); return NS_OK; }
}
// If the request was a byte range request, respond with a Content-Range
// header which details the extent of the data returned.
if (start > 0) {
static_assert (buffer_size > 1024,
"buffer_size must be large enough "
"to hold response headers");
snprintf(b, buffer_size, "Content-Range: "
"bytes %" PRId64 "-%" PRId64 "/%" PRId64 "\r\n",
start, resource->GetLength() - 1, resource->GetLength());
rv = WriteAll(b, strlen(b));
if (NS_FAILED(rv)) { Shutdown(); return NS_OK; }
}
rv = WriteAll(response_end, strlen(response_end));
if (NS_FAILED(rv)) { Shutdown(); return NS_OK; }
rv = mOutput->Flush();
if (NS_FAILED(rv)) { Shutdown(); return NS_OK; }
// Read data from media resource
uint32_t bytesRead = 0; // Number of bytes read/written to streams
rv = resource->ReadAt(start, b, buffer_size, &bytesRead);
while (NS_SUCCEEDED(rv) && bytesRead != 0) {
// Keep track of what we think the starting position for the next read
// is. This is used in subsequent ReadAt calls to ensure we are reading
// from the correct offset in the case where another thread is reading
// from th same MediaResource.
start += bytesRead;
// Write data obtained from media resource to output stream
rv = WriteAll(b, bytesRead);
if (NS_FAILED (rv)) break;
rv = resource->ReadAt(start, b, 32768, &bytesRead);
}
Shutdown();
return NS_OK;
}
