lib/context.c

   1 /*
   2  * context.c
   3  *
   4  * Babeltrace Library
   5  *
   6  * Copyright 2011-2012 EfficiOS Inc. and Linux Foundation
   7  *
   8  * Author: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   9  *         Julien Desfossez <julien.desfossez@efficios.com>
  10  *
  11  * Permission is hereby granted, free of charge, to any person obtaining a copy
  12  * of this software and associated documentation files (the "Software"), to deal
  13  * in the Software without restriction, including without limitation the rights
  14  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  15  * copies of the Software, and to permit persons to whom the Software is
  16  * furnished to do so, subject to the following conditions:
  17  *
  18  * The above copyright notice and this permission notice shall be included in
  19  * all copies or substantial portions of the Software.
  20  */
  21
  22 #include <babeltrace/babeltrace.h>
  23 #include <babeltrace/context.h>
  24 #include <babeltrace/context-internal.h>
  25 #include <babeltrace/trace-handle.h>
  26 #include <babeltrace/trace-handle-internal.h>
  27 #include <babeltrace/trace-collection.h>
  28 #include <babeltrace/format.h>
  29 #include <stdlib.h>
  30
  31 #include <fts.h>
  32 #include <fcntl.h> /* For O_RDONLY */
  33
  34 /* TODO ybrosseau: should be hidden in the CTF format */
  35 #include <babeltrace/ctf/types.h> /* for ctf_move_pos_slow */
  36
  37 #include <glib.h>
  38
  39 struct bt_context *bt_context_create(void)
  40 {
  41         struct bt_context *ctx;
  42
  43         ctx = g_new0(struct bt_context, 1);
  44         ctx->refcount = 1;
  45         /* Negative handle id are errors. */
  46         ctx->last_trace_handle_id = 0;
  47
  48         /* Instanciate the trace handle container */
  49         ctx->trace_handles = g_hash_table_new_full(g_direct_hash,
  50                                 g_direct_equal, NULL,
  51                                 (GDestroyNotify) bt_trace_handle_destroy);
  52
  53         ctx->tc = g_new0(struct trace_collection, 1);
  54         init_trace_collection(ctx->tc);
  55
  56         return ctx;
  57 }
  58
  59 int bt_context_add_trace(struct bt_context *ctx, const char *path,
  60                 const char *format_name)
  61 {
  62         struct trace_descriptor *td;
  63         struct format *fmt;
  64         struct bt_trace_handle *handle;
  65         int ret;
  66
  67         fmt = bt_lookup_format(g_quark_from_string(format_name));
  68         if (!fmt) {
  69                 fprintf(stderr, "[error] [Context] Format \"%s\" unknown.\n\n",
  70                         format_name);
  71                 ret = -1;
  72                 goto end;
  73         }
  74         td = fmt->open_trace(path, O_RDONLY,
  75                              ctf_move_pos_slow, NULL);
  76         if (!td) {
  77                 fprintf(stderr, "[error] [Context] Cannot open_trace of the format %s .\n\n",
  78                                 path);
  79                 ret = -1;
  80                 goto end;
  81         }
  82
  83         /* Create an handle for the trace */
  84         handle = bt_trace_handle_create(ctx);
  85         if (handle < 0) {
  86                 fprintf(stderr, "[error] [Context] Creating trace handle %s .\n\n",
  87                                 path);
  88                 ret = -1;
  89                 goto end;
  90         }
  91         handle->format = fmt;
  92         handle->td = td;
  93         strncpy(handle->path, path, PATH_MAX);
  94         handle->path[PATH_MAX - 1] = '\0';
  95
  96         /* Add new handle to container */
  97         g_hash_table_insert(ctx->trace_handles,
  98                 (gpointer) (unsigned long) handle->id,
  99                 handle);
 100         ret = trace_collection_add(ctx->tc, td);
 101         if (ret == 0)
 102                 return handle->id;
 103 end:
 104         return ret;
 105 }
 106
 107 void bt_context_remove_trace(struct bt_context *ctx, int handle_id)
 108 {
 109         struct bt_trace_handle *handle;
 110
 111         handle = g_hash_table_lookup(ctx->trace_handles,
 112                 (gpointer) (unsigned long) handle_id);
 113         assert(handle != NULL);
 114
 115         /* Remove from containers */
 116         trace_collection_remove(ctx->tc, handle->td);
 117         g_hash_table_remove(ctx->trace_handles,
 118                 (gpointer) (unsigned long) handle_id);
 119
 120         /* Close the trace */
 121         handle->format->close_trace(handle->td);
 122
 123         /* Destory the handle */
 124         bt_trace_handle_destroy(handle);
 125 }
 126
 127 static
 128 void bt_context_destroy(struct bt_context *ctx)
 129 {
 130         finalize_trace_collection(ctx->tc);
 131
 132         /* Remote all traces. The g_hash_table_destroy will call
 133          * bt_trace_handle_destroy on each elements.
 134          */
 135         g_hash_table_destroy(ctx->trace_handles);
 136
 137         /* ctx->tc should always be valid */
 138         assert(ctx->tc != NULL);
 139         g_free(ctx->tc);
 140         g_free(ctx);
 141 }
 142
 143 void bt_context_get(struct bt_context *ctx)
 144 {
 145         ctx->refcount++;
 146 }
 147
 148 void bt_context_put(struct bt_context *ctx)
 149 {
 150         ctx->refcount--;
 151         if (ctx->refcount == 0)
 152                 bt_context_destroy(ctx);
 153 }