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                 void (*packet_seek)(struct stream_pos *pos, size_t index,
  62                         int whence),
  63                 struct mmap_stream_list *stream_list,
  64                 FILE *metadata)
  65 {
  66         struct trace_descriptor *td;
  67         struct format *fmt;
  68         struct bt_trace_handle *handle;
  69         int ret;
  70
  71         fmt = bt_lookup_format(g_quark_from_string(format_name));
  72         if (!fmt) {
  73                 fprintf(stderr, "[error] [Context] Format \"%s\" unknown.\n\n",
  74                         format_name);
  75                 ret = -1;
  76                 goto end;
  77         }
  78         if (path) {
  79                 td = fmt->open_trace(path, O_RDONLY, packet_seek, NULL);
  80                 if (!td) {
  81                         fprintf(stderr, "[error] [Context] Cannot open_trace of the format %s .\n\n",
  82                                         path);
  83                         ret = -1;
  84                         goto end;
  85                 }
  86         } else {
  87                 td = fmt->open_mmap_trace(stream_list, packet_seek, metadata);
  88                 if (!td) {
  89                         fprintf(stderr, "[error] [Context] Cannot open_trace of the format %s .\n\n",
  90                                         path);
  91                         ret = -1;
  92                         goto end;
  93                 }
  94         }
  95
  96         /* Create an handle for the trace */
  97         handle = bt_trace_handle_create(ctx);
  98         if (handle < 0) {
  99                 fprintf(stderr, "[error] [Context] Creating trace handle %s .\n\n",
 100                                 path);
 101                 ret = -1;
 102                 goto end;
 103         }
 104         handle->format = fmt;
 105         handle->td = td;
 106         strncpy(handle->path, path, PATH_MAX);
 107         handle->path[PATH_MAX - 1] = '\0';
 108
 109         /* Add new handle to container */
 110         g_hash_table_insert(ctx->trace_handles,
 111                 (gpointer) (unsigned long) handle->id,
 112                 handle);
 113         ret = trace_collection_add(ctx->tc, td);
 114         if (ret == 0)
 115                 return handle->id;
 116 end:
 117         return ret;
 118 }
 119
 120 void bt_context_remove_trace(struct bt_context *ctx, int handle_id)
 121 {
 122         struct bt_trace_handle *handle;
 123
 124         handle = g_hash_table_lookup(ctx->trace_handles,
 125                 (gpointer) (unsigned long) handle_id);
 126         assert(handle != NULL);
 127
 128         /* Remove from containers */
 129         trace_collection_remove(ctx->tc, handle->td);
 130         g_hash_table_remove(ctx->trace_handles,
 131                 (gpointer) (unsigned long) handle_id);
 132
 133         /* Close the trace */
 134         handle->format->close_trace(handle->td);
 135
 136         /* Destory the handle */
 137         bt_trace_handle_destroy(handle);
 138 }
 139
 140 static
 141 void bt_context_destroy(struct bt_context *ctx)
 142 {
 143         finalize_trace_collection(ctx->tc);
 144
 145         /* Remote all traces. The g_hash_table_destroy will call
 146          * bt_trace_handle_destroy on each elements.
 147          */
 148         g_hash_table_destroy(ctx->trace_handles);
 149
 150         /* ctx->tc should always be valid */
 151         assert(ctx->tc != NULL);
 152         g_free(ctx->tc);
 153         g_free(ctx);
 154 }
 155
 156 void bt_context_get(struct bt_context *ctx)
 157 {
 158         ctx->refcount++;
 159 }
 160
 161 void bt_context_put(struct bt_context *ctx)
 162 {
 163         ctx->refcount--;
 164         if (ctx->refcount == 0)
 165                 bt_context_destroy(ctx);
 166 }