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 <babeltrace/babeltrace-internal.h>
  30 #include <stdlib.h>
  31 #include <string.h>
  32 #include <assert.h>
  33
  34 #include <fts.h>
  35 #include <fcntl.h> /* For O_RDONLY */
  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, NULL, NULL);
  75         if (!td) {
  76                 fprintf(stderr, "[error] [Context] Cannot open_trace of the format %s .\n\n",
  77                                 path);
  78                 ret = -1;
  79                 goto end;
  80         }
  81
  82         /* Create an handle for the trace */
  83         handle = bt_trace_handle_create(ctx);
  84         if (handle < 0) {
  85                 fprintf(stderr, "[error] [Context] Creating trace handle %s .\n\n",
  86                                 path);
  87                 ret = -1;
  88                 goto end;
  89         }
  90         handle->format = fmt;
  91         handle->td = td;
  92         strncpy(handle->path, path, PATH_MAX);
  93         handle->path[PATH_MAX - 1] = '\0';
  94
  95         /* Add new handle to container */
  96         g_hash_table_insert(ctx->trace_handles,
  97                 (gpointer) (unsigned long) handle->id,
  98                 handle);
  99         ret = trace_collection_add(ctx->tc, td);
 100         if (ret == 0)
 101                 return handle->id;
 102 end:
 103         return ret;
 104 }
 105
 106 void bt_context_remove_trace(struct bt_context *ctx, int handle_id)
 107 {
 108         struct bt_trace_handle *handle;
 109
 110         handle = g_hash_table_lookup(ctx->trace_handles,
 111                 (gpointer) (unsigned long) handle_id);
 112         assert(handle != NULL);
 113
 114         /* Remove from containers */
 115         trace_collection_remove(ctx->tc, handle->td);
 116         g_hash_table_remove(ctx->trace_handles,
 117                 (gpointer) (unsigned long) handle_id);
 118
 119         /* Close the trace */
 120         handle->format->close_trace(handle->td);
 121
 122         /* Destory the handle */
 123         bt_trace_handle_destroy(handle);
 124 }
 125
 126 static
 127 void bt_context_destroy(struct bt_context *ctx)
 128 {
 129         finalize_trace_collection(ctx->tc);
 130
 131         /* Remote all traces. The g_hash_table_destroy will call
 132          * bt_trace_handle_destroy on each elements.
 133          */
 134         g_hash_table_destroy(ctx->trace_handles);
 135
 136         /* ctx->tc should always be valid */
 137         assert(ctx->tc != NULL);
 138         g_free(ctx->tc);
 139         g_free(ctx);
 140 }
 141
 142 void bt_context_get(struct bt_context *ctx)
 143 {
 144         ctx->refcount++;
 145 }
 146
 147 void bt_context_put(struct bt_context *ctx)
 148 {
 149         ctx->refcount--;
 150         if (ctx->refcount == 0)
 151                 bt_context_destroy(ctx);
 152 }