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 #include <glib.h>
  35
  36 struct bt_context *bt_context_create(void)
  37 {
  38         struct bt_context *ctx;
  39
  40         ctx = g_new0(struct bt_context, 1);
  41         ctx->refcount = 1;
  42         /* Negative handle id are errors. */
  43         ctx->last_trace_handle_id = 0;
  44
  45         /* Instanciate the trace handle container */
  46         ctx->trace_handles = g_hash_table_new_full(g_direct_hash,
  47                                 g_direct_equal, NULL,
  48                                 (GDestroyNotify) bt_trace_handle_destroy);
  49
  50         ctx->tc = g_new0(struct trace_collection, 1);
  51         init_trace_collection(ctx->tc);
  52
  53         return ctx;
  54 }
  55
  56 int bt_context_add_trace(struct bt_context *ctx, const char *path,
  57                 const char *format_name)
  58 {
  59         struct trace_descriptor *td;
  60         struct format *fmt;
  61         struct bt_trace_handle *handle;
  62         int ret;
  63
  64         fmt = bt_lookup_format(g_quark_from_string(format_name));
  65         if (!fmt) {
  66                 fprintf(stderr, "[error] [Context] Format \"%s\" unknown.\n\n",
  67                         format_name);
  68                 ret = -1;
  69                 goto end;
  70         }
  71         td = fmt->open_trace(path, O_RDONLY, NULL, NULL);
  72         if (!td) {
  73                 fprintf(stderr, "[error] [Context] Cannot open_trace of the format %s .\n\n",
  74                                 path);
  75                 ret = -1;
  76                 goto end;
  77         }
  78
  79         /* Create an handle for the trace */
  80         handle = bt_trace_handle_create(ctx);
  81         if (handle < 0) {
  82                 fprintf(stderr, "[error] [Context] Creating trace handle %s .\n\n",
  83                                 path);
  84                 ret = -1;
  85                 goto end;
  86         }
  87         handle->format = fmt;
  88         handle->td = td;
  89         strncpy(handle->path, path, PATH_MAX);
  90         handle->path[PATH_MAX - 1] = '\0';
  91
  92         /* Add new handle to container */
  93         g_hash_table_insert(ctx->trace_handles,
  94                 (gpointer) (unsigned long) handle->id,
  95                 handle);
  96         ret = trace_collection_add(ctx->tc, td);
  97         if (ret == 0)
  98                 return handle->id;
  99 end:
 100         return ret;
 101 }
 102
 103 void bt_context_remove_trace(struct bt_context *ctx, int handle_id)
 104 {
 105         struct bt_trace_handle *handle;
 106
 107         handle = g_hash_table_lookup(ctx->trace_handles,
 108                 (gpointer) (unsigned long) handle_id);
 109         assert(handle != NULL);
 110
 111         /* Remove from containers */
 112         trace_collection_remove(ctx->tc, handle->td);
 113         g_hash_table_remove(ctx->trace_handles,
 114                 (gpointer) (unsigned long) handle_id);
 115
 116         /* Close the trace */
 117         handle->format->close_trace(handle->td);
 118
 119         /* Destory the handle */
 120         bt_trace_handle_destroy(handle);
 121 }
 122
 123 static
 124 void bt_context_destroy(struct bt_context *ctx)
 125 {
 126         finalize_trace_collection(ctx->tc);
 127
 128         /* Remote all traces. The g_hash_table_destroy will call
 129          * bt_trace_handle_destroy on each elements.
 130          */
 131         g_hash_table_destroy(ctx->trace_handles);
 132
 133         /* ctx->tc should always be valid */
 134         assert(ctx->tc != NULL);
 135         g_free(ctx->tc);
 136         g_free(ctx);
 137 }
 138
 139 void bt_context_get(struct bt_context *ctx)
 140 {
 141         ctx->refcount++;
 142 }
 143
 144 void bt_context_put(struct bt_context *ctx)
 145 {
 146         ctx->refcount--;
 147         if (ctx->refcount == 0)
 148                 bt_context_destroy(ctx);
 149 }