plugins/ctf/fs/data-stream.c

   1 /*
   2  * Copyright 2016 - Philippe Proulx <pproulx@efficios.com>
   3  * Copyright 2016 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
   4  * Copyright 2010-2011 - EfficiOS Inc. and Linux Foundation
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  19  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  22  * SOFTWARE.
  23  */
  24
  25 #include <stdio.h>
  26 #include <stdint.h>
  27 #include <stdlib.h>
  28 #include <stdbool.h>
  29 #include <glib.h>
  30 #include <inttypes.h>
  31 #include <sys/mman.h>
  32 #include <babeltrace/ctf-ir/stream.h>
  33 #include <babeltrace/plugin/notification/iterator.h>
  34 #include "file.h"
  35 #include "metadata.h"
  36 #include "../common/notif-iter/notif-iter.h"
  37 #include <assert.h>
  38
  39 #define PRINT_ERR_STREAM        ctf_fs->error_fp
  40 #define PRINT_PREFIX            "ctf-fs-data-stream"
  41 #include "print.h"
  42
  43 BT_HIDDEN
  44 void ctf_fs_stream_destroy(struct ctf_fs_stream *stream)
  45 {
  46         if (stream->file) {
  47                 ctf_fs_file_destroy(stream->file);
  48         }
  49
  50         if (stream->stream) {
  51                 BT_PUT(stream->stream);
  52         }
  53
  54         if (stream->notif_iter) {
  55                 bt_ctf_notif_iter_destroy(stream->notif_iter);
  56         }
  57
  58         g_free(stream);
  59 }
  60
  61 static size_t remaining_mmap_bytes(struct ctf_fs_stream *stream)
  62 {
  63         return stream->mmap_valid_len - stream->request_offset;
  64 }
  65
  66 static int stream_munmap(struct ctf_fs_stream *stream)
  67 {
  68         int ret = 0;
  69         struct ctf_fs_component *ctf_fs = stream->file->ctf_fs;
  70
  71         if (munmap(stream->mmap_addr, stream->mmap_len)) {
  72                 PERR("Cannot memory-unmap address %p (size %zu) of file \"%s\" (%p): %s\n",
  73                         stream->mmap_addr, stream->mmap_len,
  74                         stream->file->path->str, stream->file->fp,
  75                         strerror(errno));
  76                 ret = -1;
  77                 goto end;
  78         }
  79 end:
  80         return ret;
  81 }
  82
  83 static int mmap_next(struct ctf_fs_stream *stream)
  84 {
  85         int ret = 0;
  86         struct ctf_fs_component *ctf_fs = stream->file->ctf_fs;
  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_valid_len;
  95                 stream->request_offset = 0;
  96         }
  97
  98         stream->mmap_valid_len = MIN(stream->file->size - stream->mmap_offset,
  99                         stream->mmap_max_len);
 100         /* Round up to next page, assuming page size being a power of 2. */
 101         stream->mmap_len = (stream->mmap_valid_len + ctf_fs->page_size - 1)
 102                         & ~(ctf_fs->page_size - 1);
 103         /* Map new region */
 104         stream->mmap_addr = mmap((void *) 0, stream->mmap_len,
 105                         PROT_READ, MAP_PRIVATE, fileno(stream->file->fp),
 106                         stream->mmap_offset);
 107         if (stream->mmap_addr == MAP_FAILED) {
 108                 PERR("Cannot memory-map address (size %zu) of file \"%s\" (%p) at offset %zu: %s\n",
 109                                 stream->mmap_len, stream->file->path->str,
 110                                 stream->file->fp, stream->mmap_offset,
 111                                 strerror(errno));
 112                 goto error;
 113         }
 114
 115         goto end;
 116 error:
 117         stream_munmap(stream);
 118         ret = -1;
 119 end:
 120         return ret;
 121 }
 122
 123 static enum bt_ctf_notif_iter_medium_status medop_request_bytes(
 124                 size_t request_sz, uint8_t **buffer_addr,
 125                 size_t *buffer_sz, void *data)
 126 {
 127         enum bt_ctf_notif_iter_medium_status status =
 128                 BT_CTF_NOTIF_ITER_MEDIUM_STATUS_OK;
 129         struct ctf_fs_stream *stream = data;
 130         struct ctf_fs_component *ctf_fs = stream->file->ctf_fs;
 131
 132         if (request_sz == 0) {
 133                 goto end;
 134         }
 135
 136         /* Check if we need an initial memory map */
 137         if (!stream->mmap_addr) {
 138                 if (mmap_next(stream)) {
 139                         PERR("Cannot memory-map initial region of file \"%s\" (%p)\n",
 140                                 stream->file->path->str, stream->file->fp);
 141                         goto error;
 142                 }
 143         }
 144
 145         /* Check if we have at least one memory-mapped byte left */
 146         if (remaining_mmap_bytes(stream) == 0) {
 147                 /* Are we at the end of the file? */
 148                 if (stream->request_offset >= stream->file->size) {
 149                         PDBG("Reached end of file \"%s\" (%p)\n",
 150                                 stream->file->path->str, stream->file->fp);
 151                         status = BT_CTF_NOTIF_ITER_MEDIUM_STATUS_EOF;
 152                         goto end;
 153                 }
 154
 155                 if (mmap_next(stream)) {
 156                         PERR("Cannot memory-map next region of file \"%s\" (%p)\n",
 157                                 stream->file->path->str, stream->file->fp);
 158                         goto error;
 159                 }
 160         }
 161
 162         *buffer_sz = MIN(remaining_mmap_bytes(stream), request_sz);
 163         *buffer_addr = ((uint8_t *) stream->mmap_addr) + stream->request_offset;
 164         stream->request_offset += *buffer_sz;
 165         goto end;
 166
 167 error:
 168         status = BT_CTF_NOTIF_ITER_MEDIUM_STATUS_ERROR;
 169
 170 end:
 171         return status;
 172 }
 173
 174 static struct bt_ctf_stream *medop_get_stream(
 175                 struct bt_ctf_stream_class *stream_class, void *data)
 176 {
 177         struct ctf_fs_stream *fs_stream = data;
 178         struct ctf_fs_component *ctf_fs = fs_stream->file->ctf_fs;
 179
 180         if (!fs_stream->stream) {
 181                 int64_t id = bt_ctf_stream_class_get_id(stream_class);
 182
 183                 PDBG("Creating stream out of stream class %" PRId64 "\n", id);
 184                 fs_stream->stream = bt_ctf_stream_create(stream_class,
 185                                 fs_stream->file->path->str);
 186                 if (!fs_stream->stream) {
 187                         PERR("Cannot create stream (stream class %" PRId64 ")\n",
 188                                         id);
 189                 }
 190         }
 191
 192         return fs_stream->stream;
 193 }
 194
 195 static struct bt_ctf_notif_iter_medium_ops medops = {
 196         .request_bytes = medop_request_bytes,
 197         .get_stream = medop_get_stream,
 198 };
 199
 200 BT_HIDDEN
 201 struct ctf_fs_stream *ctf_fs_stream_create(
 202                 struct ctf_fs_component *ctf_fs, struct ctf_fs_file *file)
 203 {
 204         struct ctf_fs_stream *stream = g_new0(struct ctf_fs_stream, 1);
 205
 206         if (!stream) {
 207                 goto error;
 208         }
 209
 210         stream->file = file;
 211         stream->notif_iter = bt_ctf_notif_iter_create(ctf_fs->metadata.trace,
 212                         ctf_fs->page_size, medops, stream, ctf_fs->error_fp);
 213         if (!stream->notif_iter) {
 214                 goto error;
 215         }
 216         stream->mmap_max_len = ctf_fs->page_size * 2048;
 217         goto end;
 218 error:
 219         /* Do not touch "borrowed" file. */
 220         stream->file = NULL;
 221         ctf_fs_stream_destroy(stream);
 222         stream = NULL;
 223 end:
 224         return stream;
 225 }
 226
 227 enum bt_notification_iterator_status ctf_fs_data_stream_get_next_notification(
 228                 struct ctf_fs_component *ctf_fs,
 229                 struct bt_notification **notification,
 230                 size_t stream_id)
 231 {
 232         enum bt_ctf_notif_iter_status status;
 233         enum bt_notification_iterator_status ret;
 234         /* FIXME, only iterating on one stream for the moment. */
 235         struct ctf_fs_stream *stream = g_ptr_array_index(ctf_fs->streams,
 236                         stream_id);
 237
 238         if (stream->end_reached) {
 239                 status = BT_CTF_NOTIF_ITER_STATUS_EOF;
 240                 goto end;
 241         }
 242
 243         status = bt_ctf_notif_iter_get_next_notification(stream->notif_iter,
 244                         notification);
 245         if (status != BT_CTF_NOTIF_ITER_STATUS_OK &&
 246                         status != BT_CTF_NOTIF_ITER_STATUS_EOF) {
 247                 goto end;
 248         }
 249
 250         /* Should be handled in bt_ctf_notif_iter_get_next_notification. */
 251         if (status == BT_CTF_NOTIF_ITER_STATUS_EOF) {
 252                 *notification = bt_notification_stream_end_create(
 253                                 stream->stream);
 254                 if (!*notification) {
 255                         status = BT_CTF_NOTIF_ITER_STATUS_ERROR;
 256                 }
 257                 status = BT_CTF_NOTIF_ITER_STATUS_OK;
 258                 stream->end_reached = true;
 259         }
 260 end:
 261         switch (status) {
 262         case BT_CTF_NOTIF_ITER_STATUS_EOF:
 263                 ret = BT_NOTIFICATION_ITERATOR_STATUS_END;
 264                 break;
 265         case BT_CTF_NOTIF_ITER_STATUS_OK:
 266                 ret = BT_NOTIFICATION_ITERATOR_STATUS_OK;
 267                 break;
 268         case BT_CTF_NOTIF_ITER_STATUS_AGAIN:
 269                 /*
 270                  * Should not make it this far as this is medium-specific;
 271                  * there is nothing for the user to do and it should have been
 272                  * handled upstream.
 273                  */
 274                 assert(0);
 275         case BT_CTF_NOTIF_ITER_STATUS_INVAL:
 276                 /* No argument provided by the user, so don't return INVAL. */
 277         case BT_CTF_NOTIF_ITER_STATUS_ERROR:
 278         default:
 279                 ret = BT_NOTIFICATION_ITERATOR_STATUS_ERROR;
 280                 break;
 281         }
 282         return ret;
 283 }