c_cpp/lib/htslib/hfile_net.c

   1 /*  hfile_net.c -- network backend for low-level input/output streams.
   2
   3     Copyright (C) 2013-2015 Genome Research Ltd.
   4
   5     Author: John Marshall <jm18@sanger.ac.uk>
   6
   7 Permission is hereby granted, free of charge, to any person obtaining a copy
   8 of this software and associated documentation files (the "Software"), to deal
   9 in the Software without restriction, including without limitation the rights
  10 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  11 copies of the Software, and to permit persons to whom the Software is
  12 furnished to do so, subject to the following conditions:
  13
  14 The above copyright notice and this permission notice shall be included in
  15 all copies or substantial portions of the Software.
  16
  17 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  20 THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  22 FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  23 DEALINGS IN THE SOFTWARE.  */
  24
  25 #include <config.h>
  26
  27 #include <stdlib.h>
  28 #include <errno.h>
  29
  30 #include "hfile_internal.h"
  31
  32 #include "htslib/knetfile.h"
  33
  34 typedef struct {
  35     hFILE base;
  36     knetFile *netfp;
  37 } hFILE_net;
  38
  39 static int net_inited = 0;
  40
  41 #ifdef _WIN32
  42 static void net_exit(void)
  43 {
  44     knet_win32_destroy();
  45 }
  46 #endif
  47
  48 static int net_init(void)
  49 {
  50 #ifdef _WIN32
  51     if (knet_win32_init() != 0) return -1;
  52
  53     // In the unlikely event atexit() fails, it's better to succeed here and
  54     // carry on and do the I/O; then eventually when the program exits, we'll
  55     // merely have failed to clean up properly, as if we had aborted.
  56     (void) atexit(net_exit);
  57 #endif
  58
  59     net_inited = 1;
  60     return 0;
  61 }
  62
  63 static ssize_t net_read(hFILE *fpv, void *buffer, size_t nbytes)
  64 {
  65     hFILE_net *fp = (hFILE_net *) fpv;
  66     return knet_read(fp->netfp, buffer, nbytes);
  67 }
  68
  69 static off_t net_seek(hFILE *fpv, off_t offset, int whence)
  70 {
  71     hFILE_net *fp = (hFILE_net *) fpv;
  72     return knet_seek(fp->netfp, offset, whence);
  73 }
  74
  75 static int net_close(hFILE *fpv)
  76 {
  77     hFILE_net *fp = (hFILE_net *) fpv;
  78     return knet_close(fp->netfp);
  79 }
  80
  81 static const struct hFILE_backend net_backend =
  82 {
  83     net_read, NULL, net_seek, NULL, net_close
  84 };
  85
  86 hFILE *hopen_net(const char *filename, const char *mode)
  87 {
  88     hFILE_net *fp;
  89
  90     // Do any networking initialisation if this is the first use.
  91     if (! net_inited) { if (net_init() < 0) return NULL; }
  92
  93     fp = (hFILE_net *) hfile_init(sizeof (hFILE_net), mode, 0);
  94     if (fp == NULL) return NULL;
  95
  96     fp->netfp = knet_open(filename, mode);
  97     if (fp->netfp == NULL) { hfile_destroy((hFILE *) fp); return NULL; }
  98
  99     fp->base.backend = &net_backend;
 100     return &fp->base;
 101 }
 102
 103 int hfile_plugin_init_net(struct hFILE_plugin *self)
 104 {
 105     static const struct hFILE_scheme_handler handler =
 106         { hopen_net, hfile_always_remote, "knetfile", 0 };
 107
 108     self->name = "knetfile";
 109     hfile_add_scheme_handler("http", &handler);
 110     hfile_add_scheme_handler("ftp",  &handler);
 111     return 0;
 112 }