src/plugins/ctf/common/metadata/decoder.h

   1 #ifndef _METADATA_DECODER_H
   2 #define _METADATA_DECODER_H
   3
   4 /*
   5  * Copyright 2016-2017 - 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
  18 #include <stdint.h>
  19 #include <stdbool.h>
  20
  21 #include <babeltrace2/babeltrace.h>
  22
  23 #include "common/macros.h"
  24 #include "common/uuid.h"
  25
  26 struct ctf_trace_class;
  27
  28 /* A CTF metadata decoder object */
  29 struct ctf_metadata_decoder;
  30
  31 /* CTF metadata decoder status */
  32 enum ctf_metadata_decoder_status {
  33         CTF_METADATA_DECODER_STATUS_OK                  = 0,
  34         CTF_METADATA_DECODER_STATUS_ERROR               = -1,
  35         CTF_METADATA_DECODER_STATUS_INCOMPLETE          = -2,
  36         CTF_METADATA_DECODER_STATUS_INVAL_VERSION       = -3,
  37         CTF_METADATA_DECODER_STATUS_IR_VISITOR_ERROR    = -4,
  38 };
  39
  40 /* Decoding configuration */
  41 struct ctf_metadata_decoder_config {
  42         /* Active log level to use */
  43         bt_logging_level log_level;
  44
  45         /* Component to use for logging (can be `NULL`); weak */
  46         bt_self_component *self_comp;
  47
  48         /* Additional clock class offset to apply */
  49         int64_t clock_class_offset_s;
  50         int64_t clock_class_offset_ns;
  51
  52         /* True to create trace class objects */
  53         bool create_trace_class;
  54
  55         /*
  56          * True to keep the plain text when content is appended with
  57          * ctf_metadata_decoder_append_content().
  58          */
  59         bool keep_plain_text;
  60 };
  61
  62 /*
  63  * Creates a CTF metadata decoder.
  64  *
  65  * Returns `NULL` on error.
  66  */
  67 BT_HIDDEN
  68 struct ctf_metadata_decoder *ctf_metadata_decoder_create(
  69                 const struct ctf_metadata_decoder_config *config);
  70
  71 /*
  72  * Destroys a CTF metadata decoder that you created with
  73  * ctf_metadata_decoder_create().
  74  */
  75 BT_HIDDEN
  76 void ctf_metadata_decoder_destroy(
  77                 struct ctf_metadata_decoder *metadata_decoder);
  78
  79 /*
  80  * Appends content to the metadata decoder.
  81  *
  82  * This function reads the metadata from the current position of `fp`
  83  * until the end of this file stream.
  84  *
  85  * The metadata can be packetized or not.
  86  *
  87  * The metadata chunk needs to be complete and lexically scannable, that
  88  * is, zero or more complete top-level blocks. If it's incomplete, this
  89  * function returns `CTF_METADATA_DECODER_STATUS_INCOMPLETE`. If this
  90  * function returns `CTF_METADATA_DECODER_STATUS_INCOMPLETE`, then you
  91  * need to call it again with the _same_ metadata and more to make it
  92  * complete. For example:
  93  *
  94  *     First call:  event { name = hell
  95  *     Second call: event { name = hello_world; ... };
  96  *
  97  * If everything goes as expected, this function returns
  98  * `CTF_METADATA_DECODER_STATUS_OK`.
  99  */
 100 BT_HIDDEN
 101 enum ctf_metadata_decoder_status ctf_metadata_decoder_append_content(
 102                 struct ctf_metadata_decoder *metadata_decoder, FILE *fp);
 103
 104 /*
 105  * Returns the trace IR trace class of this metadata decoder (new
 106  * reference).
 107  *
 108  * Returns `NULL` if there's none yet or if the metadata decoder is not
 109  * configured to create trace classes.
 110  */
 111 BT_HIDDEN
 112 bt_trace_class *ctf_metadata_decoder_get_ir_trace_class(
 113                 struct ctf_metadata_decoder *mdec);
 114
 115 /*
 116  * Returns the CTF IR trace class of this metadata decoder.
 117  *
 118  * Returns `NULL` if there's none yet or if the metadata decoder is not
 119  * configured to create trace classes.
 120  */
 121 BT_HIDDEN
 122 struct ctf_trace_class *ctf_metadata_decoder_borrow_ctf_trace_class(
 123                 struct ctf_metadata_decoder *mdec);
 124
 125 /*
 126  * Checks whether or not a given metadata file stream `fp` is
 127  * packetized, setting `is_packetized` accordingly on success. On
 128  * success, also sets `*byte_order` to the byte order of the first
 129  * packet.
 130  *
 131  * This function uses `log_level` and `self_comp` for logging purposes.
 132  * `self_comp` can be `NULL` if not available.
 133  */
 134 BT_HIDDEN
 135 int ctf_metadata_decoder_is_packetized(FILE *fp, bool *is_packetized,
 136                 int *byte_order, bt_logging_level log_level,
 137                 bt_self_component *self_comp);
 138
 139 /*
 140  * Returns the byte order of the decoder's metadata stream as set by the
 141  * last call to ctf_metadata_decoder_append_content().
 142  *
 143  * Returns -1 if unknown (plain text content).
 144  */
 145 BT_HIDDEN
 146 int ctf_metadata_decoder_get_byte_order(struct ctf_metadata_decoder *mdec);
 147
 148 /*
 149  * Returns the UUID of the decoder's metadata stream as set by the last
 150  * call to ctf_metadata_decoder_append_content().
 151  *
 152  * Returns -1 if unknown (plain text content).
 153  */
 154 BT_HIDDEN
 155 int ctf_metadata_decoder_get_uuid(struct ctf_metadata_decoder *mdec,
 156                 bt_uuid_t uuid);
 157
 158 /*
 159  * Returns the metadata decoder's current metadata text.
 160  */
 161 BT_HIDDEN
 162 const char *ctf_metadata_decoder_get_text(struct ctf_metadata_decoder *mdec);
 163
 164 static inline
 165 bool ctf_metadata_decoder_is_packet_version_valid(unsigned int major,
 166                 unsigned int minor)
 167 {
 168         return major == 1 && minor == 8;
 169 }
 170
 171 #endif /* _METADATA_DECODER_H */