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 #include "data-stream.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 static
  45 size_t remaining_mmap_bytes(struct ctf_fs_stream *stream)
  46 {
  47         return stream->mmap_valid_len - stream->request_offset;
  48 }
  49
  50 static
  51 int stream_munmap(struct ctf_fs_stream *stream)
  52 {
  53         int ret = 0;
  54         struct ctf_fs_component *ctf_fs = stream->file->ctf_fs;
  55
  56         if (munmap(stream->mmap_addr, stream->mmap_len)) {
  57                 PERR("Cannot memory-unmap address %p (size %zu) of file \"%s\" (%p): %s\n",
  58                         stream->mmap_addr, stream->mmap_len,
  59                         stream->file->path->str, stream->file->fp,
  60                         strerror(errno));
  61                 ret = -1;
  62                 goto end;
  63         }
  64 end:
  65         return ret;
  66 }
  67
  68 static
  69 int mmap_next(struct ctf_fs_stream *stream)
  70 {
  71         int ret = 0;
  72         struct ctf_fs_component *ctf_fs = stream->file->ctf_fs;
  73
  74         /* Unmap old region */
  75         if (stream->mmap_addr) {
  76                 if (stream_munmap(stream)) {
  77                         goto error;
  78                 }
  79
  80                 stream->mmap_offset += stream->mmap_valid_len;
  81                 stream->request_offset = 0;
  82         }
  83
  84         stream->mmap_valid_len = MIN(stream->file->size - stream->mmap_offset,
  85                         stream->mmap_max_len);
  86         /* Round up to next page, assuming page size being a power of 2. */
  87         stream->mmap_len = (stream->mmap_valid_len + ctf_fs->page_size - 1)
  88                         & ~(ctf_fs->page_size - 1);
  89         /* Map new region */
  90         stream->mmap_addr = mmap((void *) 0, stream->mmap_len,
  91                         PROT_READ, MAP_PRIVATE, fileno(stream->file->fp),
  92                         stream->mmap_offset);
  93         if (stream->mmap_addr == MAP_FAILED) {
  94                 PERR("Cannot memory-map address (size %zu) of file \"%s\" (%p) at offset %zu: %s\n",
  95                                 stream->mmap_len, stream->file->path->str,
  96                                 stream->file->fp, stream->mmap_offset,
  97                                 strerror(errno));
  98                 goto error;
  99         }
 100
 101         goto end;
 102 error:
 103         stream_munmap(stream);
 104         ret = -1;
 105 end:
 106         return ret;
 107 }
 108
 109 static
 110 enum bt_ctf_notif_iter_medium_status medop_request_bytes(
 111                 size_t request_sz, uint8_t **buffer_addr,
 112                 size_t *buffer_sz, void *data)
 113 {
 114         enum bt_ctf_notif_iter_medium_status status =
 115                 BT_CTF_NOTIF_ITER_MEDIUM_STATUS_OK;
 116         struct ctf_fs_stream *stream = data;
 117         struct ctf_fs_component *ctf_fs = stream->file->ctf_fs;
 118
 119         if (request_sz == 0) {
 120                 goto end;
 121         }
 122
 123         /* Check if we need an initial memory map */
 124         if (!stream->mmap_addr) {
 125                 if (mmap_next(stream)) {
 126                         PERR("Cannot memory-map initial region of file \"%s\" (%p)\n",
 127                                 stream->file->path->str, stream->file->fp);
 128                         goto error;
 129                 }
 130         }
 131
 132         /* Check if we have at least one memory-mapped byte left */
 133         if (remaining_mmap_bytes(stream) == 0) {
 134                 /* Are we at the end of the file? */
 135                 if (stream->request_offset >= stream->file->size) {
 136                         PDBG("Reached end of file \"%s\" (%p)\n",
 137                                 stream->file->path->str, stream->file->fp);
 138                         status = BT_CTF_NOTIF_ITER_MEDIUM_STATUS_EOF;
 139                         goto end;
 140                 }
 141
 142                 if (mmap_next(stream)) {
 143                         PERR("Cannot memory-map next region of file \"%s\" (%p)\n",
 144                                 stream->file->path->str, stream->file->fp);
 145                         goto error;
 146                 }
 147         }
 148
 149         *buffer_sz = MIN(remaining_mmap_bytes(stream), request_sz);
 150         *buffer_addr = ((uint8_t *) stream->mmap_addr) + stream->request_offset;
 151         stream->request_offset += *buffer_sz;
 152         goto end;
 153
 154 error:
 155         status = BT_CTF_NOTIF_ITER_MEDIUM_STATUS_ERROR;
 156
 157 end:
 158         return status;
 159 }
 160
 161 static
 162 struct bt_ctf_stream *medop_get_stream(
 163                 struct bt_ctf_stream_class *stream_class, void *data)
 164 {
 165         struct ctf_fs_stream *fs_stream = data;
 166         struct ctf_fs_component *ctf_fs = fs_stream->file->ctf_fs;
 167
 168         if (!fs_stream->stream) {
 169                 int64_t id = bt_ctf_stream_class_get_id(stream_class);
 170
 171                 PDBG("Creating stream out of stream class %" PRId64 "\n", id);
 172                 fs_stream->stream = bt_ctf_stream_create(stream_class,
 173                                 fs_stream->file->path->str);
 174                 if (!fs_stream->stream) {
 175                         PERR("Cannot create stream (stream class %" PRId64 ")\n",
 176                                         id);
 177                 }
 178         }
 179
 180         return fs_stream->stream;
 181 }
 182
 183 static struct bt_ctf_notif_iter_medium_ops medops = {
 184         .request_bytes = medop_request_bytes,
 185         .get_stream = medop_get_stream,
 186 };
 187
 188 BT_HIDDEN
 189 struct ctf_fs_stream *ctf_fs_stream_create(
 190                 struct ctf_fs_component *ctf_fs, struct ctf_fs_file *file)
 191 {
 192         struct ctf_fs_stream *stream = g_new0(struct ctf_fs_stream, 1);
 193
 194         if (!stream) {
 195                 goto error;
 196         }
 197
 198         stream->file = file;
 199         stream->notif_iter = bt_ctf_notif_iter_create(ctf_fs->metadata->trace,
 200                         ctf_fs->page_size, medops, stream, ctf_fs->error_fp);
 201         if (!stream->notif_iter) {
 202                 goto error;
 203         }
 204
 205         stream->mmap_max_len = ctf_fs->page_size * 2048;
 206         goto end;
 207 error:
 208         /* Do not touch "borrowed" file. */
 209         stream->file = NULL;
 210         ctf_fs_stream_destroy(stream);
 211         stream = NULL;
 212 end:
 213         return stream;
 214 }
 215
 216 BT_HIDDEN
 217 void ctf_fs_stream_destroy(struct ctf_fs_stream *stream)
 218 {
 219         if (!stream) {
 220                 return;
 221         }
 222
 223         if (stream->file) {
 224                 ctf_fs_file_destroy(stream->file);
 225         }
 226
 227         if (stream->stream) {
 228                 BT_PUT(stream->stream);
 229         }
 230
 231         if (stream->notif_iter) {
 232                 bt_ctf_notif_iter_destroy(stream->notif_iter);
 233         }
 234
 235         g_free(stream);
 236 }