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-internal.h>
  39 #include <babeltrace/mmap-align-internal.h>
  40 #include <babeltrace/types.h>
  41
  42 struct bt_ctf_stream_pos {
  43         int fd;
  44         int prot;               /* mmap protection */
  45         int flags;              /* mmap flags */
  46
  47         /* Current position */
  48         off_t mmap_offset;      /* mmap offset in the file, in bytes */
  49         off_t mmap_base_offset; /* offset of start of packet in mmap, in bytes */
  50         uint64_t packet_size;   /* current packet 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
  73         if (pos->prot == PROT_READ) {
  74                 /*
  75                  * Reads may only reach up to the "content_size",
  76                  * regardless of the packet_size.
  77                  */
  78                 max_len = pos->offset;
  79         } else {
  80                 /* Writes may take place up to the end of the packet. */
  81                 max_len = pos->packet_size;
  82         }
  83         if (unlikely(pos->offset + bit_len > max_len))
  84                 return 0;
  85         return 1;
  86 }
  87
  88 static inline
  89 int bt_ctf_stream_pos_move(struct bt_ctf_stream_pos *pos, uint64_t bit_offset)
  90 {
  91         int ret = 0;
  92
  93         ret = bt_ctf_stream_pos_access_ok(pos, bit_offset);
  94         if (!ret) {
  95                 goto end;
  96         }
  97         pos->offset += bit_offset;
  98 end:
  99         return ret;
 100 }
 101
 102 static inline
 103 int bt_ctf_stream_pos_align(struct bt_ctf_stream_pos *pos, uint64_t bit_offset)
 104 {
 105         return bt_ctf_stream_pos_move(pos,
 106                 offset_align(pos->offset, bit_offset));
 107 }
 108
 109 static inline
 110 char *bt_ctf_stream_pos_get_addr(struct bt_ctf_stream_pos *pos)
 111 {
 112         /* Only makes sense to get the address after aligning on CHAR_BIT */
 113         assert(!(pos->offset % CHAR_BIT));
 114         return ((char *) mmap_align_addr(pos->base_mma)) +
 115                 pos->mmap_base_offset + (pos->offset / CHAR_BIT);
 116 }
 117
 118 static inline
 119 int bt_ctf_stream_pos_init(struct bt_ctf_stream_pos *pos,
 120                 int fd, int open_flags)
 121 {
 122         pos->fd = fd;
 123
 124         switch (open_flags & O_ACCMODE) {
 125         case O_RDONLY:
 126                 pos->prot = PROT_READ;
 127                 pos->flags = MAP_PRIVATE;
 128                 break;
 129         case O_RDWR:
 130                 pos->prot = PROT_READ | PROT_WRITE;
 131                 pos->flags = MAP_SHARED;
 132                 break;
 133         default:
 134                 assert(BT_FALSE);
 135         }
 136
 137         return 0;
 138 }
 139
 140 static inline
 141 int bt_ctf_stream_pos_fini(struct bt_ctf_stream_pos *pos)
 142 {
 143         if (pos->base_mma) {
 144                 int ret;
 145
 146                 /* unmap old base */
 147                 ret = munmap_align(pos->base_mma);
 148                 if (ret) {
 149                         return -1;
 150                 }
 151         }
 152
 153         return 0;
 154 }
 155
 156 BT_HIDDEN
 157 void bt_ctf_stream_pos_packet_seek(struct bt_ctf_stream_pos *pos, size_t index,
 158         int whence);
 159
 160 #endif /* BABELTRACE_CTF_WRITER_SERIALIZE_INTERNAL_H */