profile.proto

// Copyright 2016 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

// Profile is a common stacktrace profile format.
//
// Measurements represented with this format should follow the
// following conventions:
//
// - Consumers should treat unset optional fields as if they had been
//   set with their default value.
//
// - When possible, measurements should be stored in "unsampled" form
//   that is most useful to humans.  There should be enough
//   information present to determine the original sampled values.
//
// - On-disk, the serialized proto must be gzip-compressed.
//
// - The profile is represented as a set of samples, where each sample
//   references a sequence of locations, and where each location belongs
//   to a mapping.
// - There is a N->1 relationship from sample.location_id entries to
//   locations. For every sample.location_id entry there must be a
//   unique Location with that id.
// - There is an optional N->1 relationship from locations to
//   mappings. For every nonzero Location.mapping_id there must be a
//   unique Mapping with that id.

syntax = "proto3";

package perftools.profiles;

option java_package = "com.google.perftools.profiles";
option java_outer_classname = "ProfileProto";

message Profile {
  // A description of the samples associated with each Sample.value.
  // For a cpu profile this might be:
  //   [["cpu","nanoseconds"]] or [["wall","seconds"]] or [["syscall","count"]]
  // For a heap profile, this might be:
  //   [["allocations","count"], ["space","bytes"]],
  // If one of the values represents the number of events represented
  // by the sample, by convention it should be at index 0 and use
  // sample_type.unit == "count".
  repeated ValueType sample_type = 1;
  // The set of samples recorded in this profile.
  repeated Sample sample = 2;
  // Mapping from address ranges to the image/binary/library mapped
  // into that address range.  mapping[0] will be the main binary.
  repeated Mapping mapping = 3;
  // Locations referenced by samples.
  repeated Location location = 4;
  // Functions referenced by locations.
  repeated Function function = 5;
  // A common table for strings referenced by various messages.
  // string_table[0] must always be "".
  repeated string string_table = 6;
  // frames with Function.function_name fully matching the following
  // regexp will be dropped from the samples, along with their successors.
  int64 drop_frames = 7;   // Index into string table.
  // frames with Function.function_name fully matching the following
  // regexp will be kept, even if it matches drop_frames.
  int64 keep_frames = 8;  // Index into string table.

  // The following fields are informational, do not affect
  // interpretation of results.

  // Time of collection (UTC) represented as nanoseconds past the epoch.
  int64 time_nanos = 9;
  // Duration of the profile, if a duration makes sense.
  int64 duration_nanos = 10;
  // The kind of events between sampled occurrences.
  // e.g [ "cpu","cycles" ] or [ "heap","bytes" ]
  ValueType period_type = 11;
  // The number of events between sampled occurrences.
  int64 period = 12;
  // Free-form text associated with the profile. The text is displayed as is
  // to the user by the tools that read profiles (e.g. by pprof). This field
  // should not be used to store any machine-readable information, it is only
  // for human-friendly content. The profile must stay functional if this field
  // is cleaned.
  repeated int64 comment = 13; // Indices into string table.
  // Index into the string table of the type of the preferred sample
  // value. If unset, clients should default to the last sample value.
  int64 default_sample_type = 14;
}

// ValueType describes the semantics and measurement units of a value.
message ValueType {
  int64 type = 1; // Index into string table.
  int64 unit = 2; // Index into string table.
}

// Each Sample records values encountered in some program
// context. The program context is typically a stack trace, perhaps
// augmented with auxiliary information like the thread-id, some
// indicator of a higher level request being handled etc.
message Sample {
  // The ids recorded here correspond to a Profile.location.id.
  // The leaf is at location_id[0].
  repeated uint64 location_id = 1;
  // The type and unit of each value is defined by the corresponding
  // entry in Profile.sample_type. All samples must have the same
  // number of values, the same as the length of Profile.sample_type.
  // When aggregating multiple samples into a single sample, the
  // result has a list of values that is the element-wise sum of the
  // lists of the originals.
  repeated int64 value = 2;
  // label includes additional context for this sample. It can include
  // things like a thread id, allocation size, etc.
  //
  // NOTE: While possible, having multiple values for the same label key is
  // strongly discouraged and should never be used. Most tools (e.g. pprof) do
  // not have good (or any) support for multi-value labels. And an even more
  // discouraged case is having a string label and a numeric label of the same
  // name on a sample.  Again, possible to express, but should not be used.
  repeated Label label = 3;
}

message Label {
  // Index into string table. An annotation for a sample (e.g.
  // "allocation_size") with an associated value.
  // Keys with "pprof::" prefix are reserved for internal use by pprof.
  int64 key = 1;

  // At most one of the following must be present
  int64 str = 2;   // Index into string table
  int64 num = 3;

  // Should only be present when num is present.
  // Specifies the units of num.
  // Use arbitrary string (for example, "requests") as a custom count unit.
  // If no unit is specified, consumer may apply heuristic to deduce the unit.
  // Consumers may also  interpret units like "bytes" and "kilobytes" as memory
  // units and units like "seconds" and "nanoseconds" as time units,
  // and apply appropriate unit conversions to these.
  int64 num_unit = 4;  // Index into string table
}

message Mapping {
  // Unique nonzero id for the mapping.
  uint64 id = 1;
  // Address at which the binary (or DLL) is loaded into memory.
  uint64 memory_start = 2;
  // The limit of the address range occupied by this mapping.
  uint64 memory_limit = 3;
  // Offset in the binary that corresponds to the first mapped address.
  uint64 file_offset = 4;
  // The object this entry is loaded from.  This can be a filename on
  // disk for the main binary and shared libraries, or virtual
  // abstractions like "[vdso]".
  int64 filename = 5;  // Index into string table
  // A string that uniquely identifies a particular program version
  // with high probability. E.g., for binaries generated by GNU tools,
  // it could be the contents of the .note.gnu.build-id field.
  int64 build_id = 6;  // Index into string table

  // The following fields indicate the resolution of symbolic info.
  bool has_functions = 7;
  bool has_filenames = 8;
  bool has_line_numbers = 9;
  bool has_inline_frames = 10;
}

// Describes function and line table debug information.
message Location {
  // Unique nonzero id for the location.  A profile could use
  // instruction addresses or any integer sequence as ids.
  uint64 id = 1;
  // The id of the corresponding profile.Mapping for this location.
  // It can be unset if the mapping is unknown or not applicable for
  // this profile type.
  uint64 mapping_id = 2;
  // The instruction address for this location, if available.  It
  // should be within [Mapping.memory_start...Mapping.memory_limit]
  // for the corresponding mapping. A non-leaf address may be in the
  // middle of a call instruction. It is up to display tools to find
  // the beginning of the instruction if necessary.
  uint64 address = 3;
  // Multiple line indicates this location has inlined functions,
  // where the last entry represents the caller into which the
  // preceding entries were inlined.
  //
  // E.g., if memcpy() is inlined into printf:
  //    line[0].function_name == "memcpy"
  //    line[1].function_name == "printf"
  repeated Line line = 4;
  // Provides an indication that multiple symbols map to this location's
  // address, for example due to identical code folding by the linker. In that
  // case the line information above represents one of the multiple
  // symbols. This field must be recomputed when the symbolization state of the
  // profile changes.
  bool is_folded = 5;
}

message Line {
  // The id of the corresponding profile.Function for this line.
  uint64 function_id = 1;
  // Line number in source code.
  int64 line = 2;
  // Column number in source code.
  int64 column = 3;
}

message Function {
  // Unique nonzero id for the function.
  uint64 id = 1;
  // Name of the function, in human-readable form if available.
  int64 name = 2; // Index into string table
  // Name of the function, as identified by the system.
  // For instance, it can be a C++ mangled name.
  int64 system_name = 3; // Index into string table
  // Source file containing the function.
  int64 filename = 4; // Index into string table
  // Line number in source file.
  int64 start_line = 5;
}