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
  25 /* A CTF metadata decoder object */
  26 struct ctf_metadata_decoder;
  27
  28 /* CTF metadata decoder status */
  29 enum ctf_metadata_decoder_status {
  30         CTF_METADATA_DECODER_STATUS_OK                  = 0,
  31         CTF_METADATA_DECODER_STATUS_ERROR               = -1,
  32         CTF_METADATA_DECODER_STATUS_INCOMPLETE          = -2,
  33         CTF_METADATA_DECODER_STATUS_INVAL_VERSION       = -3,
  34         CTF_METADATA_DECODER_STATUS_IR_VISITOR_ERROR    = -4,
  35 };
  36
  37 /* Decoding configuration */
  38 struct ctf_metadata_decoder_config {
  39         bt_logging_level log_level;
  40         int64_t clock_class_offset_s;
  41         int64_t clock_class_offset_ns;
  42 };
  43
  44 /*
  45  * Creates a CTF metadata decoder.
  46  *
  47  * Returns `NULL` on error.
  48  */
  49 BT_HIDDEN
  50 struct ctf_metadata_decoder *ctf_metadata_decoder_create(
  51                 bt_self_component_source *self_comp,
  52                 const struct ctf_metadata_decoder_config *config);
  53
  54 /*
  55  * Destroys a CTF metadata decoder that you created with
  56  * ctf_metadata_decoder_create().
  57  */
  58 BT_HIDDEN
  59 void ctf_metadata_decoder_destroy(
  60                 struct ctf_metadata_decoder *metadata_decoder);
  61
  62 /*
  63  * Decodes a new chunk of CTF metadata.
  64  *
  65  * This function reads the metadata from the current position of `fp`
  66  * until the end of this file stream. If it finds new information (new
  67  * event class, new stream class, or new clock class), it appends this
  68  * information to the decoder's trace object (as returned by
  69  * ctf_metadata_decoder_get_ir_trace_class()), or it creates this trace.
  70  *
  71  * The metadata can be packetized or not.
  72  *
  73  * The metadata chunk needs to be complete and scannable, that is,
  74  * zero or more complete top-level blocks. If it's incomplete, this
  75  * function returns `CTF_METADATA_DECODER_STATUS_INCOMPLETE`. If this
  76  * function returns `CTF_METADATA_DECODER_STATUS_INCOMPLETE`, then you
  77  * need to call it again with the same metadata and more to make it
  78  * complete. For example:
  79  *
  80  *     First call:  event { name = hell
  81  *     Second call: event { name = hello_world; ... };
  82  *
  83  * If the conversion from the metadata text to CTF IR objects fails,
  84  * this function returns `CTF_METADATA_DECODER_STATUS_IR_VISITOR_ERROR`.
  85  *
  86  * If everything goes as expected, this function returns
  87  * `CTF_METADATA_DECODER_STATUS_OK`.
  88  */
  89 BT_HIDDEN
  90 enum ctf_metadata_decoder_status ctf_metadata_decoder_decode(
  91                 struct ctf_metadata_decoder *metadata_decoder, FILE *fp);
  92
  93 BT_HIDDEN
  94 bt_trace_class *ctf_metadata_decoder_get_ir_trace_class(
  95                 struct ctf_metadata_decoder *mdec);
  96
  97 BT_HIDDEN
  98 struct ctf_trace_class *ctf_metadata_decoder_borrow_ctf_trace_class(
  99                 struct ctf_metadata_decoder *mdec);
 100
 101 /*
 102  * Checks whether or not a given metadata file stream is packetized, and
 103  * if so, sets `*byte_order` to the byte order of the first packet.
 104  */
 105 BT_HIDDEN
 106 bool ctf_metadata_decoder_is_packetized(FILE *fp, int *byte_order,
 107                 bt_logging_level log_level);
 108
 109 /*
 110  * Decodes a packetized metadata file stream to a NULL-terminated
 111  * text buffer using the given byte order.
 112  */
 113 BT_HIDDEN
 114 int ctf_metadata_decoder_packetized_file_stream_to_buf(
 115                 FILE *fp, char **buf, int byte_order,
 116                 bt_logging_level log_level);
 117
 118 #endif /* _METADATA_DECODER_H */