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_str)
  61 {
  62         struct trace_descriptor *td;
  63         struct format *fmt;
  64         struct bt_trace_handle *handle;
  65
  66         fmt = bt_lookup_format(g_quark_from_string(format_str));
  67         td = fmt->open_trace(path, O_RDONLY,
  68                              ctf_move_pos_slow, NULL);
  69         if (!td) {
  70                 fprintf(stdout, "[error] [Context] Cannot open_trace of the format %s .\n\n",
  71                                 path);
  72                 return -1;
  73         }
  74
  75         /* Create an handle for the trace */
  76         handle = bt_trace_handle_create(ctx);
  77         if (handle < 0) {
  78                 fprintf(stdout, "[error] [Context] Creating trace handle %s .\n\n",
  79                                 path);
  80                 return -1;
  81         }
  82         handle->format = fmt;
  83         handle->td = td;
  84         strncpy(handle->path, path, PATH_MAX);
  85         handle->path[PATH_MAX - 1] = '\0';
  86
  87         /* Add new handle to container */
  88         g_hash_table_insert(ctx->trace_handles,
  89                 (gpointer) (unsigned long) handle->id,
  90                 handle);
  91         trace_collection_add(ctx->tc, td);
  92         return 0;
  93 }
  94
  95 /*
  96  * Unable to open toplevel: failure.
  97  * Unable to open some subdirectory or file: warn and continue;
  98  */
  99 int bt_context_add_traces_recursive(struct bt_context *ctx, const char *path,
 100                 const char *format_str)
 101 {
 102         FTS *tree;
 103         FTSENT *node;
 104         GArray *trace_ids;
 105         char lpath[PATH_MAX];
 106         char * const paths[2] = { lpath, NULL };
 107         int ret;
 108
 109         /*
 110          * Need to copy path, because fts_open can change it.
 111          * It is the pointer array, not the strings, that are constant.
 112          */
 113         strncpy(lpath, path, PATH_MAX);
 114         lpath[PATH_MAX - 1] = '\0';
 115
 116         tree = fts_open(paths, FTS_NOCHDIR | FTS_LOGICAL, 0);
 117         if (tree == NULL) {
 118                 fprintf(stdout, "[error] Cannot traverse \"%s\" for reading.\n\n",
 119                                 path);
 120                 return -EINVAL;
 121         }
 122
 123         trace_ids = g_array_new(FALSE, TRUE, sizeof(int));
 124
 125         while ((node = fts_read(tree))) {
 126                 int dirfd, metafd;
 127
 128                 if (!(node->fts_info & FTS_D))
 129                         continue;
 130
 131                 dirfd = open(node->fts_accpath, 0);
 132                 if (dirfd < 0) {
 133                         fprintf(stdout, "[warning] unable to open trace "
 134                                 "directory file descriptor.\n");
 135                         continue;
 136                 }
 137                 metafd = openat(dirfd, "metadata", O_RDONLY);
 138                 if (metafd < 0) {
 139                         ret = close(dirfd);
 140                         if (ret < 0) {
 141                                 perror("close");
 142                                 goto error;
 143                         }
 144                 } else {
 145                         int trace_id;
 146
 147                         ret = close(metafd);
 148                         if (ret < 0) {
 149                                 perror("close");
 150                                 goto error;
 151                         }
 152                         ret = close(dirfd);
 153                         if (ret < 0) {
 154                                 perror("close");
 155                                 goto error;
 156                         }
 157
 158                         trace_id = bt_context_add_trace(ctx,
 159                                 node->fts_accpath, format_str);
 160                         if (trace_id < 0) {
 161                                 fprintf(stdout, "[warning] CTX opening trace \"%s\"from %s "
 162                                         "for reading.\n\n", node->fts_accpath, path);
 163                                 continue;
 164                         }
 165                         g_array_append_val(trace_ids, trace_id);
 166                 }
 167         }
 168
 169         g_array_free(trace_ids, TRUE);
 170         return 0;
 171
 172 error:
 173         return ret;
 174 }
 175
 176 void bt_context_remove_trace(struct bt_context *ctx, int handle_id)
 177 {
 178         struct bt_trace_handle *handle;
 179
 180         handle = g_hash_table_lookup(ctx->trace_handles,
 181                 (gpointer) (unsigned long) handle_id);
 182         assert(handle != NULL);
 183
 184         /* Remove from containers */
 185         trace_collection_remove(ctx->tc, handle->td);
 186         g_hash_table_remove(ctx->trace_handles,
 187                 (gpointer) (unsigned long) handle_id);
 188
 189         /* Close the trace */
 190         handle->format->close_trace(handle->td);
 191
 192         /* Destory the handle */
 193         bt_trace_handle_destroy(handle);
 194 }
 195
 196 static
 197 void bt_context_destroy(struct bt_context *ctx)
 198 {
 199         finalize_trace_collection(ctx->tc);
 200
 201         /* Remote all traces. The g_hash_table_destroy will call
 202          * bt_trace_handle_destroy on each elements.
 203          */
 204         g_hash_table_destroy(ctx->trace_handles);
 205
 206         /* ctx->tc should always be valid */
 207         assert(ctx->tc != NULL);
 208         g_free(ctx->tc);
 209         g_free(ctx);
 210 }
 211
 212 void bt_context_get(struct bt_context *ctx)
 213 {
 214         ctx->refcount++;
 215 }
 216
 217 void bt_context_put(struct bt_context *ctx)
 218 {
 219         ctx->refcount--;
 220         if (ctx->refcount == 0)
 221                 bt_context_destroy(ctx);
 222 }