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(stderr, "[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(stderr, "[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         return trace_collection_add(ctx->tc, td);
  92 }
  93
  94 /*
  95  * Unable to open toplevel: failure.
  96  * Unable to open some subdirectory or file: warn and continue;
  97  */
  98 int bt_context_add_traces_recursive(struct bt_context *ctx, const char *path,
  99                 const char *format_str)
 100 {
 101         FTS *tree;
 102         FTSENT *node;
 103         GArray *trace_ids;
 104         char lpath[PATH_MAX];
 105         char * const paths[2] = { lpath, NULL };
 106         int ret;
 107
 108         /*
 109          * Need to copy path, because fts_open can change it.
 110          * It is the pointer array, not the strings, that are constant.
 111          */
 112         strncpy(lpath, path, PATH_MAX);
 113         lpath[PATH_MAX - 1] = '\0';
 114
 115         tree = fts_open(paths, FTS_NOCHDIR | FTS_LOGICAL, 0);
 116         if (tree == NULL) {
 117                 fprintf(stderr, "[error] [Context] Cannot traverse \"%s\" for reading.\n",
 118                                 path);
 119                 return -EINVAL;
 120         }
 121
 122         trace_ids = g_array_new(FALSE, TRUE, sizeof(int));
 123
 124         while ((node = fts_read(tree))) {
 125                 int dirfd, metafd;
 126
 127                 if (!(node->fts_info & FTS_D))
 128                         continue;
 129
 130                 dirfd = open(node->fts_accpath, 0);
 131                 if (dirfd < 0) {
 132                         fprintf(stderr, "[error] [Context] Unable to open trace "
 133                                 "directory file descriptor.\n");
 134                         ret = dirfd;
 135                         goto error;
 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(stderr, "[error] [Context] opening trace \"%s\" from %s "
 162                                         "for reading.\n", node->fts_accpath, path);
 163                                 ret = trace_id;
 164                                 goto error;
 165                         }
 166                         g_array_append_val(trace_ids, trace_id);
 167                 }
 168         }
 169
 170         g_array_free(trace_ids, TRUE);
 171         return 0;
 172
 173 error:
 174         return ret;
 175 }
 176
 177 void bt_context_remove_trace(struct bt_context *ctx, int handle_id)
 178 {
 179         struct bt_trace_handle *handle;
 180
 181         handle = g_hash_table_lookup(ctx->trace_handles,
 182                 (gpointer) (unsigned long) handle_id);
 183         assert(handle != NULL);
 184
 185         /* Remove from containers */
 186         trace_collection_remove(ctx->tc, handle->td);
 187         g_hash_table_remove(ctx->trace_handles,
 188                 (gpointer) (unsigned long) handle_id);
 189
 190         /* Close the trace */
 191         handle->format->close_trace(handle->td);
 192
 193         /* Destory the handle */
 194         bt_trace_handle_destroy(handle);
 195 }
 196
 197 static
 198 void bt_context_destroy(struct bt_context *ctx)
 199 {
 200         finalize_trace_collection(ctx->tc);
 201
 202         /* Remote all traces. The g_hash_table_destroy will call
 203          * bt_trace_handle_destroy on each elements.
 204          */
 205         g_hash_table_destroy(ctx->trace_handles);
 206
 207         /* ctx->tc should always be valid */
 208         assert(ctx->tc != NULL);
 209         g_free(ctx->tc);
 210         g_free(ctx);
 211 }
 212
 213 void bt_context_get(struct bt_context *ctx)
 214 {
 215         ctx->refcount++;
 216 }
 217
 218 void bt_context_put(struct bt_context *ctx)
 219 {
 220         ctx->refcount--;
 221         if (ctx->refcount == 0)
 222                 bt_context_destroy(ctx);
 223 }