src/comm/Read.h

   1 /*
   2  * Copyright (C) 1996-2017 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 #include "sbuf/forward.h"
  16
  17 namespace Comm
  18 {
  19
  20 /**
  21  * Start monitoring for read.
  22  *
  23  * callback is scheduled when the read is possible,
  24  * or on file descriptor close.
  25  */
  26 void Read(const Comm::ConnectionPointer &conn, AsyncCall::Pointer &callback);
  27
  28 /// whether the FD socket is being monitored for read
  29 bool MonitorsRead(int fd);
  30
  31 /**
  32  * Perform a read(2) on a connection immediately.
  33  *
  34  * If params.size is non-zero will limit size of the read to either
  35  * the buffer free space or params.size, whichever is smallest.
  36  *
  37  * The returned flag is also placed in params.flag.
  38  *
  39  * \retval Comm::OK          data has been read and placed in buf, amount in params.size
  40  * \retval Comm::COMM_ERROR  an error occured, the code is placed in params.xerrno
  41  * \retval Comm::INPROGRESS  unable to read at this time, or a minor error occured
  42  * \retval Comm::ENDFILE     0-byte read has occured.
  43  *                           Usually indicates the remote end has disconnected.
  44  */
  45 Comm::Flag ReadNow(CommIoCbParams &params, SBuf &buf);
  46
  47 /// Cancel the read pending on FD. No action if none pending.
  48 void ReadCancel(int fd, AsyncCall::Pointer &callback);
  49
  50 /// callback handler to process an FD which is available for reading
  51 extern PF HandleRead;
  52
  53 } // namespace Comm
  54
  55 // Legacy API to be removed
  56 void comm_read_base(const Comm::ConnectionPointer &conn, char *buf, int len, AsyncCall::Pointer &callback);
  57 inline void comm_read(const Comm::ConnectionPointer &conn, char *buf, int len, AsyncCall::Pointer &callback)
  58 {
  59     assert(buf != NULL);
  60     comm_read_base(conn, buf, len, callback);
  61 }
  62 void comm_read_cancel(int fd, IOCB *callback, void *data);
  63
  64 #endif /* _SQUID_COMM_READ_H */
  65