class TypedProtoDecoderBase

Defined at line 376 of file ../../third_party/perfetto/include/perfetto/protozero/proto_decoder.h

This decoder loads all fields upfront, without recursing in nested messages.

It is used as a base class for typed decoders generated by the pbzero plugin.

The split between TypedProtoDecoderBase and TypedProtoDecoder

> is to have

unique definition of functions like ParseAllFields() and ExpandHeapStorage().

The storage (either on-stack or on-heap) for this class is organized as

follows:

|-------------------------- fields_ ----------------------|

[ field 0 (invalid) ] [ fields 1 .. N ] [ repeated fields ]

^ ^

num_fields_ size_

Note that if a message has high field numbers, upon creation |size_| can be

|num_fields_| (until a heap expansion is hit while inserting).

Protected Members

unique_ptr heap_storage_

Field * fields_

uint64_t * presence_

uint32_t num_fields_

uint32_t size_

bool has_out_of_range_fields_

uint32_t capacity_

static Field kInvalidField

Public Methods

const Field & Get (uint32_t id)

If the field |id| is known at compile time, prefer the templated

specialization at

<kFieldNumber

>().

Defined at line 380 of file ../../third_party/perfetto/include/perfetto/protozero/proto_decoder.h

bool has_out_of_range_fields ()

True if the message contained at least one field with an id beyond the

highest id known in-tree (typically an out-of-tree extension). Such

fields are not stored here; this lets callers skip a selective re-decode

via unknown_fields() when there is nothing to find.

Defined at line 394 of file ../../third_party/perfetto/include/perfetto/protozero/proto_decoder.h

bool HasAnyField (const uint64_t * mask, size_t words)

True if any field whose bit is set in |mask| is present. |mask| is laid

out like the presence bitmap (bit i of word i / 64 for field id i) and

holds |words| words; bits beyond the known field range are ignored.

Defined at line 399 of file ../../third_party/perfetto/include/perfetto/protozero/proto_decoder.h

bool HasField (uint32_t id)

True if the field with the given id was seen while decoding: tests bit

|id| of the presence bitmap. The caller must check that |id| is within

the bitmap, i.e.

= the decoder's MAX_FIELD_ID. Note that |id| may

exceed |num_fields_|: the selective decoding constructor shrinks

num_fields_ to the mask's extent but clears the full bitmap, so that

>() can keep testing the bit directly.

Defined at line 414 of file ../../third_party/perfetto/include/perfetto/protozero/proto_decoder.h

template <typename T>

RepeatedFieldIterator<T> GetRepeated (uint32_t field_id)

Returns an object that allows to iterate over all instances of a repeated

field given its id. Example usage:

for (auto it = decoder.GetRepeated

<int32

_t>(N); it; ++it) { ... }

Defined at line 425 of file ../../third_party/perfetto/include/perfetto/protozero/proto_decoder.h

template <proto_utils::ProtoWireType wire_type, typename cpp_type>

PackedRepeatedFieldIterator<wire_type, cpp_type> GetPackedRepeated (uint32_t field_id, bool * parse_error_location)

Returns an objects that allows to iterate over all entries of a packed

repeated field given its id and type. The |wire_type| is necessary for

decoding the packed field, the |cpp_type| is for convenience

stronger

typing.

The caller must also supply a pointer to a bool that is set to true if the

packed buffer is found to be malformed while iterating (so you need to

exhaust the iterator if you want to check the full extent of the buffer).

Note that unlike standard protobuf parsers, protozero does not allow

treating of packed repeated fields as non-packed and vice-versa (therefore

not making the packed option forwards and backwards compatible). So

the caller needs to use the right accessor for correct results.

Defined at line 463 of file ../../third_party/perfetto/include/perfetto/protozero/proto_decoder.h

template <proto_utils::ProtoWireType wire_type, typename cpp_type>

UnifiedRepeatedFieldIterator<wire_type, cpp_type> GetUnifiedRepeated (uint32_t field_id, bool * parse_error_location)

Returns a unified iterator that automatically dispatches between packed and

non-packed repeated field iteration based on the wire format. This allows

parsers to handle both formats without knowing ahead of time which one is

used.

Example usage:

bool parse_error = false;

for (auto it = decoder.GetUnifiedRepeated

<wire

_type, int32_t>(N,

&parse

_error);

it; ++it) { ... }

Defined at line 487 of file ../../third_party/perfetto/include/perfetto/protozero/proto_decoder.h

Protected Methods

void ParseAllFields ()

void ParseAllFieldsSelective (const uint64_t * dense_mask, Field ** spill, uint32_t * spill_capacity, uint32_t * spill_size, std::unique_ptr<Field[]> * heap_spill)

Selective-decoding flavour, driven by SelectiveTypedProtoDecoder. The

spill arguments are in/out and deliberately arguments rather than

members: as members they would cost an initialization per decoder

construction (decoders are constructed per nested message). |*spill| is

repointed at |*heap_spill| if its capacity is exhausted.

void ExpandHeapStorage ()

Called when the default on-stack storage is exhausted and new repeated

fields need to be pushed.

void TypedProtoDecoderBase (Field * storage, uint64_t * presence, uint32_t num_fields, uint32_t capacity, const uint8_t * buffer, size_t length)

Defined at line 507 of file ../../third_party/perfetto/include/perfetto/protozero/proto_decoder.h

void SetField (uint32_t id)

Marks the field with the given id as seen: sets bit |id| of the presence

bitmap. |id| must be

num_fields_.

Defined at line 536 of file ../../third_party/perfetto/include/perfetto/protozero/proto_decoder.h