src/comm/Read.h

   1 /*
   2  * Copyright (C) 1996-2014 The Squid Software Foundation and contributors
   3  *
   4  * Squid software is distributed under GPLv2+ license and includes
   5  * contributions from numerous individuals and organizations.
   6  * Please see the COPYING and CONTRIBUTORS files for details.
   7  */
   8
   9 #ifndef _SQUID_COMM_READ_H
  10 #define _SQUID_COMM_READ_H
  11
  12 #include "base/AsyncCall.h"
  13 #include "comm/forward.h"
  14 #include "CommCalls.h"
  15
  16 class SBuf;
  17
  18 namespace Comm
  19 {
  20
  21 /**
  22  * Start monitoring for read.
  23  *
  24  * callback is scheduled when the read is possible,
  25  * or on file descriptor close.
  26  */
  27 void Read(const Comm::ConnectionPointer &conn, AsyncCall::Pointer &callback);
  28
  29 /// whether the FD socket is being monitored for read
  30 bool MonitorsRead(int fd);
  31
  32 /**
  33  * Perform a read(2) on a connection immediately.
  34  *
  35  * The returned flag is also placed in params.flag.
  36  *
  37  * \retval Comm::OK          data has been read and placed in buf, amount in params.size
  38  * \retval Comm::COMM_ERROR  an error occured, the code is placed in params.xerrno
  39  * \retval Comm::INPROGRESS  unable to read at this time, or a minor error occured
  40  * \retval Comm::ENDFILE     0-byte read has occured.
  41  *                           Usually indicates the remote end has disconnected.
  42  */
  43 Comm::Flag ReadNow(CommIoCbParams &params, SBuf &buf);
  44
  45 /// Cancel the read pending on FD. No action if none pending.
  46 void ReadCancel(int fd, AsyncCall::Pointer &callback);
  47
  48 /// callback handler to process an FD which is available for reading
  49 extern PF HandleRead;
  50
  51 } // namespace Comm
  52
  53 // Legacy API to be removed
  54 void comm_read_base(const Comm::ConnectionPointer &conn, char *buf, int len, AsyncCall::Pointer &callback);
  55 inline void comm_read(const Comm::ConnectionPointer &conn, char *buf, int len, AsyncCall::Pointer &callback)
  56 {
  57     assert(buf != NULL);
  58     comm_read_base(conn, buf, len, callback);
  59 }
  60 void comm_read_cancel(int fd, IOCB *callback, void *data);
  61
  62 #endif /* _SQUID_COMM_READ_H */
  63