// BamHttp_p.cpp (c) 2011 Derek Barnett
// Marth Lab, Department of Biology, Boston College
// ---------------------------------------------------------------------------
-// Last modified: 8 November 2011 (DB)
+// Last modified: 8 December 2011 (DB)
// ---------------------------------------------------------------------------
// Provides reading/writing of BAM files on HTTP server
// ***************************************************************************
static const string HTTP_PORT = "80";
static const string HTTP_PREFIX = "http://";
static const size_t HTTP_PREFIX_LENGTH = 7;
-static const char COLON_CHAR = ':';
-static const char SLASH_CHAR = '/';
+
+static const string DOUBLE_NEWLINE = "\n\n";
+
+static const string GET_METHOD = "GET";
+static const string HOST_HEADER = "Host";
+static const string RANGE_HEADER = "Range";
+static const string BYTES_PREFIX = "bytes=";
+
+static const char HOST_SEPARATOR = '/';
+static const char PROXY_SEPARATOR = ':';
// -----------------
// utility methods
return;
// find end of host name portion (first '/' hit after the prefix)
- const size_t firstSlashFound = tempUrl.find(SLASH_CHAR, HTTP_PREFIX_LENGTH);
+ const size_t firstSlashFound = tempUrl.find(HOST_SEPARATOR, HTTP_PREFIX_LENGTH);
if ( firstSlashFound == string::npos ) {
; // no slash found... no filename given along with host?
}
// fetch hostname (check for proxy port)
string hostname = tempUrl.substr(HTTP_PREFIX_LENGTH, (firstSlashFound - HTTP_PREFIX_LENGTH));
- const size_t colonFound = hostname.find(COLON_CHAR);
+ const size_t colonFound = hostname.find(PROXY_SEPARATOR);
if ( colonFound != string::npos ) {
; // TODO: handle proxy port (later, just skip for now)
} else {
// try to read 'remainingBytes' from socket
const int64_t socketBytesRead = ReadFromSocket(data+bytesReadSoFar, remainingBytes);
- if ( socketBytesRead < 0 )
+ if ( socketBytesRead < 0 ) // error
return -1;
+ else if ( socketBytesRead == 0 ) // EOF
+ return bytesReadSoFar;
bytesReadSoFar += socketBytesRead;
m_filePosition += socketBytesRead;
}
// there is data left from last request
if ( m_endRangeFilePosition > m_filePosition ) {
- // try to read either the total 'remainingBytes' or whatever we have remaining from last request range
+ // try to read either the total 'remainingBytes' or
+ // whatever we have remaining from last request range
const size_t rangeRemainingBytes = m_endRangeFilePosition - m_filePosition;
const size_t bytesToRead = std::min(remainingBytes, rangeRemainingBytes);
const int64_t socketBytesRead = ReadFromSocket(data+bytesReadSoFar, bytesToRead);
- if ( socketBytesRead < 0 )
+ if ( socketBytesRead < 0 ) // error
return -1;
+ else if ( socketBytesRead == 0 ) // EOF
+ return bytesReadSoFar;
bytesReadSoFar += socketBytesRead;
m_filePosition += socketBytesRead;
}
- // otherwise, this is a 1st-time read OR we already read everything from the last GET request
+ // otherwise, this is a 1st-time read or
+ // we already read everything from the last GET request
else {
// request for next range
}
int64_t BamHttp::ReadFromSocket(char* data, const unsigned int maxNumBytes) {
-
- // try to read 'remainingBytes' from socket
- const int64_t numBytesRead = m_socket->Read(data, maxNumBytes);
- if ( numBytesRead < 0 )
- return -1;
- return numBytesRead;
+ return m_socket->Read(data, maxNumBytes);
}
bool BamHttp::ReceiveResponse(void) {
// fetch header, up until double new line
string responseHeader;
- static const string doubleNewLine = "\n\n";
do {
// read line & append to full header
const string headerLine = m_socket->ReadLine();
responseHeader += headerLine;
- } while ( !endsWith(responseHeader, doubleNewLine) );
+ } while ( !endsWith(responseHeader, DOUBLE_NEWLINE) );
// sanity check
if ( responseHeader.empty() ) {
RaiiBuffer tmp(0x8000);
int64_t numBytesRead = 0;
while ( numBytesRead < m_filePosition ) {
- int64_t result = ReadFromSocket(tmp.Buffer, 0x8000);
- if ( result < 0 ) {
+
+ const int64_t remaining = m_filePosition - numBytesRead;
+ const size_t bytesToRead = static_cast<size_t>( (remaining > 0x8000) ? 0x8000 : remaining );
+ const int64_t socketBytesRead = ReadFromSocket(tmp.Buffer, bytesToRead);
+ if ( socketBytesRead < 0 ) { // error
Close();
return false;
}
- numBytesRead += result;
+ else if ( socketBytesRead == 0 ) // EOF
+ break;
+
+ numBytesRead += socketBytesRead;
}
// return success
- return true;
+ return ( numBytesRead == m_filePosition);
}
// on any other reponse status
return false;
}
-bool BamHttp::Seek(const int64_t& position) {
+bool BamHttp::Seek(const int64_t& position, const int origin) {
// if HTTP device not in a valid state
if ( !IsOpen() ) {
// discard socket's buffer contents, update positions, & return success
m_socket->ClearBuffer();
- m_filePosition = position;
- m_endRangeFilePosition = position;
+
+ if ( origin == SEEK_CUR )
+ m_filePosition += position;
+ else if ( origin == SEEK_SET )
+ m_filePosition = position;
+ else {
+ // TODO: set error string
+ return false;
+ }
+ m_endRangeFilePosition = m_filePosition;
return true;
}
// create range string
m_endRangeFilePosition = m_filePosition + numBytes;
stringstream range("");
- range << "bytes=" << m_filePosition << "-" << m_endRangeFilePosition;
+ range << BYTES_PREFIX << m_filePosition << '-' << m_endRangeFilePosition;
// make sure we're connected
if ( !EnsureSocketConnection() )
return false;
// create request
- m_request = new HttpRequestHeader("GET", m_filename);
- m_request->SetField("Host", m_hostname);
- m_request->SetField("Range", range.str());
+ m_request = new HttpRequestHeader(GET_METHOD, m_filename);
+ m_request->SetField(HOST_HEADER, m_hostname);
+ m_request->SetField(RANGE_HEADER, range.str());
// write request to socket
const string requestHeader = m_request->ToString();
projects / bamtools.git / blobdiff