include/babeltrace/ctf/types.h

   1 #ifndef _BABELTRACE_CTF_TYPES_H
   2 #define _BABELTRACE_CTF_TYPES_H
   3
   4 /*
   5  * Common Trace Format
   6  *
   7  * Type header
   8  *
   9  * Copyright 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  10  *
  11  * Permission is hereby granted, free of charge, to any person obtaining a copy
  12  * of this software and associated documentation files (the "Software"), to deal
  13  * in the Software without restriction, including without limitation the rights
  14  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  15  * copies of the Software, and to permit persons to whom the Software is
  16  * furnished to do so, subject to the following conditions:
  17  *
  18  * The above copyright notice and this permission notice shall be included in
  19  * all copies or substantial portions of the Software.
  20  */
  21
  22 #include <babeltrace/types.h>
  23 #include <sys/types.h>
  24 #include <sys/stat.h>
  25 #include <fcntl.h>
  26 #include <sys/mman.h>
  27 #include <errno.h>
  28 #include <stdint.h>
  29 #include <unistd.h>
  30 #include <glib.h>
  31
  32 struct packet_index {
  33         off_t offset;           /* offset of the packet in the file, in bytes */
  34         size_t packet_size;     /* packet size, in bits */
  35         size_t content_size;    /* content size, in bits */
  36 };
  37
  38 /*
  39  * Always update ctf_stream_pos with ctf_move_pos and ctf_init_pos.
  40  */
  41 struct ctf_stream_pos {
  42         struct stream_pos parent;
  43         int fd;                 /* backing file fd. -1 if unset. */
  44         GArray *packet_index;   /* contains struct packet_index */
  45         int prot;               /* mmap protection */
  46         int flags;              /* mmap flags */
  47
  48         /* Current position */
  49         off_t mmap_offset;      /* mmap offset in the file, in bytes */
  50         size_t packet_size;     /* current packet size, in bits */
  51         size_t content_size;    /* current content size, in bits */
  52         uint32_t *content_size_loc; /* pointer to current content size */
  53         char *base;             /* mmap base address */
  54         size_t offset;          /* offset from base, in bits */
  55         size_t cur_index;       /* current index in packet index */
  56
  57         int dummy;              /* dummy position, for length calculation */
  58 };
  59
  60 static inline
  61 struct ctf_stream_pos *ctf_pos(struct stream_pos *pos)
  62 {
  63         return container_of(pos, struct ctf_stream_pos, parent);
  64 }
  65
  66 /*
  67  * IMPORTANT: All lengths (len) and offsets (start, end) are expressed in bits,
  68  *            *not* in bytes.
  69  *
  70  * All write primitives, as well as read for dynamically sized entities, can
  71  * receive a NULL ptr/dest parameter. In this case, no write is performed, but
  72  * the size is returned.
  73  */
  74
  75 void ctf_integer_read(struct stream_pos *pos, struct definition *definition);
  76 void ctf_integer_write(struct stream_pos *pos, struct definition *definition);
  77 void ctf_float_read(struct stream_pos *pos, struct definition *definition);
  78 void ctf_float_write(struct stream_pos *pos, struct definition *definition);
  79 void ctf_string_read(struct stream_pos *pos, struct definition *definition);
  80 void ctf_string_write(struct stream_pos *pos, struct definition *definition);
  81 void ctf_enum_read(struct stream_pos *pos, struct definition *definition);
  82 void ctf_enum_write(struct stream_pos *pos, struct definition *definition);
  83 void ctf_struct_rw(struct stream_pos *pos, struct definition *definition);
  84 void ctf_variant_rw(struct stream_pos *pos, struct definition *definition);
  85 void ctf_array_rw(struct stream_pos *pos, struct definition *definition);
  86 void ctf_sequence_rw(struct stream_pos *pos, struct definition *definition);
  87
  88 void ctf_move_pos_slow(struct ctf_stream_pos *pos, size_t offset);
  89
  90 void ctf_init_pos(struct ctf_stream_pos *pos, int fd, int open_flags);
  91 void ctf_fini_pos(struct ctf_stream_pos *pos);
  92
  93 /*
  94  * move_pos - move position of a relative bit offset
  95  *
  96  * TODO: allow larger files by updating base too.
  97  */
  98 static inline
  99 void ctf_move_pos(struct ctf_stream_pos *pos, size_t bit_offset)
 100 {
 101         if (pos->fd >= 0) {
 102                 if (((pos->prot == PROT_READ)
 103                       && (pos->offset + bit_offset >= pos->content_size))
 104                     || ((pos->prot == PROT_WRITE)
 105                       && (pos->offset + bit_offset >= pos->packet_size))) {
 106                         ctf_move_pos_slow(pos, bit_offset);
 107                         return;
 108                 }
 109         }
 110         pos->offset += bit_offset;
 111 }
 112
 113 /*
 114  * align_pos - align position on a bit offset (> 0)
 115  *
 116  * TODO: allow larger files by updating base too.
 117  */
 118 static inline
 119 void ctf_align_pos(struct ctf_stream_pos *pos, size_t bit_offset)
 120 {
 121         ctf_move_pos(pos, offset_align(pos->offset, bit_offset));
 122 }
 123
 124 static inline
 125 char *ctf_get_pos_addr(struct ctf_stream_pos *pos)
 126 {
 127         /* Only makes sense to get the address after aligning on CHAR_BIT */
 128         assert(!(pos->offset % CHAR_BIT));
 129         return pos->base + (pos->offset / CHAR_BIT);
 130 }
 131
 132 static inline
 133 void ctf_dummy_pos(struct ctf_stream_pos *pos, struct ctf_stream_pos *dummy)
 134 {
 135         memcpy(dummy, pos, sizeof(struct ctf_stream_pos));
 136         dummy->dummy = 1;
 137         dummy->fd = -1;
 138 }
 139
 140 /*
 141  * Check if current packet can hold data.
 142  * Returns 0 for success, negative error otherwise.
 143  */
 144 static inline
 145 int ctf_pos_packet(struct ctf_stream_pos *dummy)
 146 {
 147         if (dummy->offset > dummy->packet_size)
 148                 return -ENOSPC;
 149         return 0;
 150 }
 151
 152 static inline
 153 void ctf_pos_pad_packet(struct ctf_stream_pos *pos)
 154 {
 155         ctf_move_pos(pos, pos->packet_size - pos->offset);
 156 }
 157
 158 #endif /* _BABELTRACE_CTF_TYPES_H */