include/babeltrace/ctf-writer/serialize-internal.h

   1 #ifndef BABELTRACE_CTF_WRITER_SERIALIZE_INTERNAL_H
   2 #define BABELTRACE_CTF_WRITER_SERIALIZE_INTERNAL_H
   3
   4 /*
   5  * Copyright 2017 Philippe Proulx <pproulx@efficios.com>
   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  * The Common Trace Format (CTF) Specification is available at
  26  * http://www.efficios.com/ctf
  27  */
  28
  29 #include <stdint.h>
  30 #include <limits.h>
  31 #include <sys/mman.h>
  32 #include <sys/types.h>
  33 #include <sys/stat.h>
  34 #include <fcntl.h>
  35 #include <babeltrace/ctf-ir/field-types.h>
  36 #include <babeltrace/ctf-ir/fields.h>
  37 #include <babeltrace/ctf-ir/fields-internal.h>
  38 #include <babeltrace/align.h>
  39 #include <babeltrace/mmap-align.h>
  40
  41 struct bt_ctf_stream_pos {
  42         int fd;
  43         int prot;               /* mmap protection */
  44         int flags;              /* mmap flags */
  45
  46         /* Current position */
  47         off_t mmap_offset;      /* mmap offset in the file, in bytes */
  48         off_t mmap_base_offset; /* offset of start of packet in mmap, in bytes */
  49         uint64_t packet_size;   /* current packet size, in bits */
  50         uint64_t content_size;  /* current content size, in bits */
  51         int64_t offset;         /* offset from base, in bits. EOF for end of file. */
  52         struct mmap_align *base_mma;/* mmap base address */
  53 };
  54
  55 BT_HIDDEN
  56 int bt_ctf_field_integer_write(struct bt_ctf_field_integer *field,
  57                 struct bt_ctf_stream_pos *pos,
  58                 enum bt_ctf_byte_order native_byte_order);
  59
  60 BT_HIDDEN
  61 int bt_ctf_field_floating_point_write(struct bt_ctf_field_floating_point *field,
  62                 struct bt_ctf_stream_pos *pos,
  63                 enum bt_ctf_byte_order native_byte_order);
  64
  65 static inline
  66 int bt_ctf_stream_pos_access_ok(struct bt_ctf_stream_pos *pos, uint64_t bit_len)
  67 {
  68         uint64_t max_len;
  69
  70         if (unlikely(pos->offset == EOF))
  71                 return 0;
  72         if (pos->prot == PROT_READ) {
  73                 /*
  74                  * Reads may only reach up to the "content_size",
  75                  * regardless of the packet_size.
  76                  */
  77                 max_len = pos->content_size;
  78         } else {
  79                 /* Writes may take place up to the end of the packet. */
  80                 max_len = pos->packet_size;
  81         }
  82         if (unlikely(pos->offset + bit_len > max_len))
  83                 return 0;
  84         return 1;
  85 }
  86
  87 static inline
  88 int bt_ctf_stream_pos_move(struct bt_ctf_stream_pos *pos, uint64_t bit_offset)
  89 {
  90         int ret = 0;
  91
  92         ret = bt_ctf_stream_pos_access_ok(pos, bit_offset);
  93         if (!ret) {
  94                 goto end;
  95         }
  96         pos->offset += bit_offset;
  97 end:
  98         return ret;
  99 }
 100
 101 static inline
 102 int bt_ctf_stream_pos_align(struct bt_ctf_stream_pos *pos, uint64_t bit_offset)
 103 {
 104         return bt_ctf_stream_pos_move(pos,
 105                 offset_align(pos->offset, bit_offset));
 106 }
 107
 108 static inline
 109 char *bt_ctf_stream_pos_get_addr(struct bt_ctf_stream_pos *pos)
 110 {
 111         /* Only makes sense to get the address after aligning on CHAR_BIT */
 112         assert(!(pos->offset % CHAR_BIT));
 113         return mmap_align_addr(pos->base_mma) +
 114                 pos->mmap_base_offset + (pos->offset / CHAR_BIT);
 115 }
 116
 117 static inline
 118 int bt_ctf_stream_pos_init(struct bt_ctf_stream_pos *pos,
 119                 int fd, int open_flags)
 120 {
 121         pos->fd = fd;
 122
 123         switch (open_flags & O_ACCMODE) {
 124         case O_RDONLY:
 125                 pos->prot = PROT_READ;
 126                 pos->flags = MAP_PRIVATE;
 127                 break;
 128         case O_RDWR:
 129                 pos->prot = PROT_READ | PROT_WRITE;
 130                 pos->flags = MAP_SHARED;
 131                 break;
 132         default:
 133                 assert(false);
 134         }
 135
 136         return 0;
 137 }
 138
 139 static inline
 140 int bt_ctf_stream_pos_fini(struct bt_ctf_stream_pos *pos)
 141 {
 142         if (pos->base_mma) {
 143                 int ret;
 144
 145                 /* unmap old base */
 146                 ret = munmap_align(pos->base_mma);
 147                 if (ret) {
 148                         return -1;
 149                 }
 150         }
 151
 152         return 0;
 153 }
 154
 155 BT_HIDDEN
 156 void bt_ctf_stream_pos_packet_seek(struct bt_ctf_stream_pos *pos, size_t index,
 157         int whence);
 158
 159 #endif /* BABELTRACE_CTF_WRITER_SERIALIZE_INTERNAL_H */