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