plugins/ctf/fs/data-stream.c

   1 /*
   2  * Copyright 2016 - Philippe Proulx <pproulx@efficios.com>
   3  * Copyright 2010-2011 - EfficiOS Inc. and Linux Foundation
   4  *
   5  * Some functions are based on older functions written by Mathieu Desnoyers.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a copy
   8  * of this software and associated documentation files (the "Software"), to deal
   9  * in the Software without restriction, including without limitation the rights
  10  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  11  * copies of the Software, and to permit persons to whom the Software is
  12  * furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included in
  15  * all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  20  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  23  * SOFTWARE.
  24  */
  25
  26 #include <stdio.h>
  27 #include <stdint.h>
  28 #include <stdlib.h>
  29 #include <stdbool.h>
  30 #include <glib.h>
  31 #include <inttypes.h>
  32 #include <sys/mman.h>
  33 #include <babeltrace/ctf-ir/stream.h>
  34 #include <babeltrace/plugin/notification/iterator.h>
  35 #include "file.h"
  36 #include "metadata.h"
  37 #include "../common/notif-iter/notif-iter.h"
  38 #include <assert.h>
  39
  40 #define PRINT_ERR_STREAM        ctf_fs->error_fp
  41 #define PRINT_PREFIX            "ctf-fs-data-stream"
  42 #include "print.h"
  43
  44 BT_HIDDEN
  45 void ctf_fs_stream_destroy(struct ctf_fs_stream *stream)
  46 {
  47         if (stream->file) {
  48                 ctf_fs_file_destroy(stream->file);
  49         }
  50
  51         if (stream->stream) {
  52                 BT_PUT(stream->stream);
  53         }
  54
  55         if (stream->notif_iter) {
  56                 bt_ctf_notif_iter_destroy(stream->notif_iter);
  57         }
  58
  59         g_free(stream);
  60 }
  61
  62 static size_t remaining_mmap_bytes(struct ctf_fs_stream *stream)
  63 {
  64         return stream->mmap_offset + stream->mmap_len -
  65                 stream->request_offset;
  66 }
  67
  68 static int stream_munmap(struct ctf_fs_stream *stream)
  69 {
  70         struct ctf_fs_component *ctf_fs = stream->file->ctf_fs;
  71
  72         if (munmap(stream->mmap_addr, stream->mmap_len)) {
  73                 PERR("Cannot memory-unmap address %p (size %zu) of file \"%s\" (%p): %s\n",
  74                         stream->mmap_addr, stream->mmap_len,
  75                         stream->file->path->str, stream->file->fp,
  76                         strerror(errno));
  77                 return -1;
  78         }
  79
  80         return 0;
  81 }
  82
  83 static int mmap_next(struct ctf_fs_stream *stream)
  84 {
  85         struct ctf_fs_component *ctf_fs = stream->file->ctf_fs;
  86         int ret = 0;
  87
  88         /* Unmap old region */
  89         if (stream->mmap_addr) {
  90                 if (stream_munmap(stream)) {
  91                         goto error;
  92                 }
  93
  94                 stream->mmap_offset += stream->mmap_len;
  95                 stream->request_offset = stream->mmap_offset;
  96         }
  97
  98         /* Map new region */
  99         stream->mmap_addr = mmap((void *) 0, stream->mmap_len,
 100                         PROT_READ, MAP_PRIVATE, fileno(stream->file->fp),
 101                         stream->mmap_offset);
 102         if (stream->mmap_addr == MAP_FAILED) {
 103                 PERR("Cannot memory-map address (size %zu) of file \"%s\" (%p) at offset %zu: %s\n",
 104                                 stream->mmap_len, stream->file->path->str,
 105                                 stream->file->fp, stream->mmap_offset,
 106                                 strerror(errno));
 107                 goto error;
 108         }
 109
 110         goto end;
 111 error:
 112         stream_munmap(stream);
 113         ret = -1;
 114 end:
 115         return ret;
 116 }
 117
 118 static enum bt_ctf_notif_iter_medium_status medop_request_bytes(
 119                 size_t request_sz, uint8_t **buffer_addr,
 120                 size_t *buffer_sz, void *data)
 121 {
 122         enum bt_ctf_notif_iter_medium_status status =
 123                 BT_CTF_NOTIF_ITER_MEDIUM_STATUS_OK;
 124         struct ctf_fs_stream *stream = data;
 125         struct ctf_fs_component *ctf_fs = stream->file->ctf_fs;
 126
 127         if (request_sz == 0) {
 128                 goto end;
 129         }
 130
 131         /* Check if we need an initial memory map */
 132         if (!stream->mmap_addr) {
 133                 if (mmap_next(stream)) {
 134                         PERR("Cannot memory-map initial region of file \"%s\" (%p)\n",
 135                                 stream->file->path->str, stream->file->fp);
 136                         goto error;
 137                 }
 138         }
 139
 140         /* Check if we have at least one memory-mapped byte left */
 141         if (remaining_mmap_bytes(stream) == 0) {
 142                 /* Are we at the end of the file? */
 143                 if (stream->request_offset == stream->file->size) {
 144                         PDBG("Reached end of file \"%s\" (%p)\n",
 145                                 stream->file->path->str, stream->file->fp);
 146                         status = BT_CTF_NOTIF_ITER_MEDIUM_STATUS_EOF;
 147                         goto end;
 148                 }
 149
 150                 if (mmap_next(stream)) {
 151                         PERR("Cannot memory-map next region of file \"%s\" (%p)\n",
 152                                 stream->file->path->str, stream->file->fp);
 153                         goto error;
 154                 }
 155         }
 156
 157         *buffer_sz = MIN(remaining_mmap_bytes(stream), request_sz);
 158         *buffer_addr = ((uint8_t *) stream->mmap_addr) +
 159                 stream->request_offset - stream->mmap_offset;
 160         stream->request_offset += *buffer_sz;
 161         goto end;
 162
 163 error:
 164         status = BT_CTF_NOTIF_ITER_MEDIUM_STATUS_ERROR;
 165
 166 end:
 167         return status;
 168 }
 169
 170 static struct bt_ctf_stream *medop_get_stream(
 171                 struct bt_ctf_stream_class *stream_class, void *data)
 172 {
 173         struct ctf_fs_stream *fs_stream = data;
 174         struct ctf_fs_component *ctf_fs = fs_stream->file->ctf_fs;
 175
 176         if (!fs_stream->stream) {
 177                 int64_t id = bt_ctf_stream_class_get_id(stream_class);
 178
 179                 PDBG("Creating stream out of stream class %" PRId64 "\n", id);
 180                 fs_stream->stream = bt_ctf_stream_create(stream_class,
 181                         fs_stream->file->path->str);
 182                 if (!fs_stream->stream) {
 183                         PERR("Cannot create stream (stream class %" PRId64 ")\n",
 184                                 id);
 185                 }
 186         }
 187
 188         return fs_stream->stream;
 189 }
 190
 191 static struct bt_ctf_notif_iter_medium_ops medops = {
 192         .request_bytes = medop_request_bytes,
 193         .get_stream = medop_get_stream,
 194 };
 195
 196 BT_HIDDEN
 197 struct ctf_fs_stream *ctf_fs_stream_create(
 198                 struct ctf_fs_component *ctf_fs, struct ctf_fs_file *file)
 199 {
 200         struct ctf_fs_stream *stream = g_new0(struct ctf_fs_stream, 1);
 201
 202         if (!stream) {
 203                 goto error;
 204         }
 205
 206         stream->file = file;
 207         stream->notif_iter = bt_ctf_notif_iter_create(ctf_fs->metadata.trace,
 208                         ctf_fs->page_size, medops, stream, ctf_fs->error_fp);
 209         if (!stream->notif_iter) {
 210                 goto error;
 211         }
 212         stream->mmap_len = ctf_fs->page_size * 2048;
 213         goto end;
 214 error:
 215         /* Do not touch "borrowed" file. */
 216         stream->file = NULL;
 217         ctf_fs_stream_destroy(stream);
 218         stream = NULL;
 219 end:
 220         return stream;
 221 }
 222
 223 enum bt_notification_iterator_status ctf_fs_data_stream_get_next_notification(
 224                 struct ctf_fs_component *ctf_fs,
 225                 struct bt_notification **notification)
 226 {
 227         enum bt_ctf_notif_iter_status status;
 228         enum bt_notification_iterator_status ret;
 229         /* FIXME, only iterating on one stream for the moment. */
 230         struct ctf_fs_stream *stream = g_ptr_array_index(ctf_fs->streams, 0);
 231
 232         if (stream->end_reached) {
 233                 status = BT_CTF_NOTIF_ITER_STATUS_EOF;
 234                 goto end;
 235         }
 236
 237         status = bt_ctf_notif_iter_get_next_notification(stream->notif_iter,
 238                         notification);
 239         if (status != BT_CTF_NOTIF_ITER_STATUS_OK &&
 240                         status != BT_CTF_NOTIF_ITER_STATUS_EOF) {
 241                 goto end;
 242         }
 243
 244         /* Should be handled in bt_ctf_notif_iter_get_next_notification. */
 245         if (status == BT_CTF_NOTIF_ITER_STATUS_EOF) {
 246                 *notification = bt_notification_stream_end_create(
 247                                 stream->stream);
 248                 if (!*notification) {
 249                         status = BT_CTF_NOTIF_ITER_STATUS_ERROR;
 250                 }
 251                 status = BT_CTF_NOTIF_ITER_STATUS_OK;
 252                 stream->end_reached = true;
 253         }
 254 end:
 255         switch (status) {
 256         case BT_CTF_NOTIF_ITER_STATUS_EOF:
 257                 ret = BT_NOTIFICATION_ITERATOR_STATUS_END;
 258                 break;
 259         case BT_CTF_NOTIF_ITER_STATUS_OK:
 260                 ret = BT_NOTIFICATION_ITERATOR_STATUS_OK;
 261                 break;
 262         case BT_CTF_NOTIF_ITER_STATUS_AGAIN:
 263                 /*
 264                  * Should not make it this far as this is medium-specific;
 265                  * there is nothing for the user to do and it should have been
 266                  * handled upstream.
 267                  */
 268                 assert(0);
 269         case BT_CTF_NOTIF_ITER_STATUS_INVAL:
 270                 /* No argument provided by the user, so don't return INVAL. */
 271         case BT_CTF_NOTIF_ITER_STATUS_ERROR:
 272         default:
 273                 ret = BT_NOTIFICATION_ITERATOR_STATUS_ERROR;
 274                 break;
 275         }
 276         return ret;
 277 }