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Use TLV-based encoding for ember data buffer. (project-chip#36172)
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* Use TLV-based encoding for ember data buffer.

This saves 2K of flash on some test devices, being much more
efficient in code size compared to using datamodel code.

* Restyled by clang-format

* Restyled by shfmt

* Undo unrelated change

* Add some casts to make android compiler happy

* Updates based on code review

* Added unit tests for min/max int64 values

* Rename PascalString to PascalStringType

* Fix rename

* Restyle

* Add helper methods inside odd sized integers to localize code logic

* Restyled by clang-format

* Fix up negative ranges

* Fixed ranges

* Fix signed max bug and update unit tests

* Make android happy

* Typo fix

* Switch up unit tests

* Update a nullable check to make use of ValueToNullValue

* Add namespace prefix

* Update src/app/codegen-data-model-provider/EmberDataBuffer.cpp

Co-authored-by: Boris Zbarsky <[email protected]>

* Update src/app/codegen-data-model-provider/EmberDataBuffer.h

Co-authored-by: Boris Zbarsky <[email protected]>

* Correct comments:signed, not unsigned

* Use constructors for the buffer info

* Rename things to EmberAttributeDataBuffer

* Undo submodule updates

* Restyled by clang-format

---------

Co-authored-by: Restyled.io <[email protected]>
Co-authored-by: Andrei Litvin <[email protected]>
Co-authored-by: Boris Zbarsky <[email protected]>
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@andy31415 @restyled-commits
@andreilitvin @bzbarsky-apple
4 people authored Oct 24, 2024
1 parent ab04f03 commit 9423a8c
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Showing 12 changed files with 1,124 additions and 205 deletions.
12 changes: 9 additions & 3 deletions scripts/build_coverage.sh
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Original file line number Diff line number Diff line change
Expand Up @@ -50,6 +50,7 @@ SUPPORTED_TESTS=(unit yaml all)
CODE="core"
TESTS="unit"
skip_gn=false
TEST_TARGET=check

help() {

Expand All @@ -70,6 +71,7 @@ help() {
'unit': Run unit test to drive the coverage check. --default
'yaml': Run yaml test to drive the coverage check.
'all': Run unit & yaml test to drive the coverage check.
--target Specific test target to run (e.g. TestEmberAttributeBuffer.run)
"
}

Expand All @@ -89,6 +91,9 @@ for i in "$@"; do
TESTS="${i#*=}"
shift
;;
--target=*)
TEST_TARGET="${i#*=}"
;;
-o=* | --output_root=*)
OUTPUT_ROOT="${i#*=}"
COVERAGE_ROOT="$OUTPUT_ROOT/coverage"
Expand Down Expand Up @@ -121,20 +126,21 @@ if [ "$skip_gn" == false ]; then
# Generates ninja files
EXTRA_GN_ARGS=""
if [[ "$TESTS" == "yaml" || "$TESTS" == "all" ]]; then
EXTRA_GN_ARGS="$EXTRA_GN_ARGS chip_build_all_clusters_app=true"
EXTRA_GN_ARGS="$EXTRA_GN_ARGS chip_build_all_clusters_app=true"
else
EXTRA_GN_ARGS="$EXTRA_GN_ARGS chip_build_tools=false"
fi
gn --root="$CHIP_ROOT" gen "$OUTPUT_ROOT" --args="use_coverage=true$EXTRA_GN_ARGS"
ninja -C "$OUTPUT_ROOT"

# Run unit tests
if [[ "$TESTS" == "unit" || "$TESTS" == "all" ]]; then
ninja -C "$OUTPUT_ROOT" check
ninja -C "$OUTPUT_ROOT" "$TEST_TARGET"
fi

# Run yaml tests
if [[ "$TESTS" == "yaml" || "$TESTS" == "all" ]]; then
ninja -C "$OUTPUT_ROOT"

scripts/run_in_build_env.sh \
"./scripts/tests/run_test_suite.py \
--chip-tool ""$OUTPUT_ROOT/chip-tool \
Expand Down
2 changes: 2 additions & 0 deletions src/app/codegen-data-model-provider/BUILD.gn
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Original file line number Diff line number Diff line change
Expand Up @@ -24,6 +24,8 @@ import("//build_overrides/chip.gni")
# CodegenDataModelProvider.h
# CodegenDataModelProvider_Read.cpp
# CodegenDataModelProvider_Write.cpp
# EmberAttributeDataBuffer.cpp
# EmberAttributeDataBuffer.h
# EmberMetadata.cpp
# EmberMetadata.h
# Instance.cpp
Expand Down
198 changes: 5 additions & 193 deletions src/app/codegen-data-model-provider/CodegenDataModelProvider_Write.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -21,6 +21,7 @@
#include <app/AttributeAccessInterface.h>
#include <app/AttributeAccessInterfaceRegistry.h>
#include <app/RequiredPrivilege.h>
#include <app/codegen-data-model-provider/EmberAttributeDataBuffer.h>
#include <app/codegen-data-model-provider/EmberMetadata.h>
#include <app/data-model/FabricScoped.h>
#include <app/reporting/reporting.h>
Expand Down Expand Up @@ -85,198 +86,6 @@ std::optional<CHIP_ERROR> TryWriteViaAccessInterface(const ConcreteDataAttribute
return decoder.TriedDecode() ? std::make_optional(CHIP_NO_ERROR) : std::nullopt;
}

/// Metadata of what a ember/pascal short string means (prepended by a u8 length)
struct ShortPascalString
{
using LengthType = uint8_t;
static constexpr LengthType kNullLength = 0xFF;

static void SetLength(uint8_t * buffer, LengthType value) { *buffer = value; }
};

/// Metadata of what a ember/pascal LONG string means (prepended by a u16 length)
struct LongPascalString
{
using LengthType = uint16_t;
static constexpr LengthType kNullLength = 0xFFFF;

// Encoding for ember string lengths is little-endian (see ember-strings.cpp)
static void SetLength(uint8_t * buffer, LengthType value) { Encoding::LittleEndian::Put16(buffer, value); }
};

// ember assumptions ... should just work
static_assert(sizeof(ShortPascalString::LengthType) == 1);
static_assert(sizeof(LongPascalString::LengthType) == 2);

/// Convert the value stored in 'decoder' into an ember format span 'out'
///
/// The value converted will be of type T (e.g. CharSpan or ByteSpan) and it will be converted
/// via the given ENCODING (i.e. ShortPascalString or LongPascalString)
///
/// isNullable defines if the value of NULL is allowed to be converted.
template <typename T, class ENCODING>
CHIP_ERROR DecodeStringLikeIntoEmberBuffer(AttributeValueDecoder decoder, bool isNullable, MutableByteSpan & out)
{
T workingValue;

if (isNullable)
{
typename DataModel::Nullable<T> nullableWorkingValue;
ReturnErrorOnFailure(decoder.Decode(nullableWorkingValue));

if (nullableWorkingValue.IsNull())
{
VerifyOrReturnError(out.size() >= sizeof(typename ENCODING::LengthType), CHIP_ERROR_BUFFER_TOO_SMALL);
ENCODING::SetLength(out.data(), ENCODING::kNullLength);
out.reduce_size(sizeof(typename ENCODING::LengthType));
return CHIP_NO_ERROR;
}

// continue encoding non-null value
workingValue = nullableWorkingValue.Value();
}
else
{
ReturnErrorOnFailure(decoder.Decode(workingValue));
}

auto len = static_cast<typename ENCODING::LengthType>(workingValue.size());
VerifyOrReturnError(out.size() >= sizeof(len) + len, CHIP_ERROR_BUFFER_TOO_SMALL);

uint8_t * output_buffer = out.data();

ENCODING::SetLength(output_buffer, len);
output_buffer += sizeof(len);

memcpy(output_buffer, workingValue.data(), workingValue.size());
output_buffer += workingValue.size();

out.reduce_size(static_cast<size_t>(output_buffer - out.data()));
return CHIP_NO_ERROR;
}

/// Decodes a numeric data value of type T from the `decoder` into a ember-encoded buffer `out`
///
/// isNullable defines if the value of NULL is allowed to be decoded.
template <typename T>
CHIP_ERROR DecodeIntoEmberBuffer(AttributeValueDecoder & decoder, bool isNullable, MutableByteSpan & out)
{
using Traits = NumericAttributeTraits<T>;
typename Traits::StorageType storageValue;

if (isNullable)
{
DataModel::Nullable<typename Traits::WorkingType> workingValue;
ReturnErrorOnFailure(decoder.Decode(workingValue));

if (workingValue.IsNull())
{
Traits::SetNull(storageValue);
}
else
{
// This guards against trying to decode something that overlaps nullable, for example
// Nullable<uint8_t>(0xFF) is not representable because 0xFF is the encoding of NULL in ember
// as well as odd-sized integers (e.g. full 32-bit value like 0x11223344 cannot be written
// to a 3-byte odd-sized integger).
VerifyOrReturnError(Traits::CanRepresentValue(isNullable, workingValue.Value()), CHIP_ERROR_INVALID_ARGUMENT);
Traits::WorkingToStorage(workingValue.Value(), storageValue);
}

VerifyOrReturnError(out.size() >= sizeof(storageValue), CHIP_ERROR_INVALID_ARGUMENT);
}
else
{
typename Traits::WorkingType workingValue;
ReturnErrorOnFailure(decoder.Decode(workingValue));

Traits::WorkingToStorage(workingValue, storageValue);

VerifyOrReturnError(out.size() >= sizeof(storageValue), CHIP_ERROR_INVALID_ARGUMENT);

// Even non-nullable values may be outside range: e.g. odd-sized integers have working values
// that are larger than the storage values (e.g. a uint32_t being stored as a 3-byte integer)
VerifyOrReturnError(Traits::CanRepresentValue(isNullable, workingValue), CHIP_ERROR_INVALID_ARGUMENT);
}

const uint8_t * data = Traits::ToAttributeStoreRepresentation(storageValue);

// The decoding + ToAttributeStoreRepresentation will result in data being
// stored in native format/byteorder, suitable to directly be stored in the data store
memcpy(out.data(), data, sizeof(storageValue));
out.reduce_size(sizeof(storageValue));

return CHIP_NO_ERROR;
}

/// Read the data from "decoder" into an ember-formatted buffer "out"
///
/// `out` is a in/out buffer:
/// - its initial size determines the maximum size of the buffer
/// - its output size reflects the actual data size
///
/// Uses the attribute `metadata` to determine how the data is to be encoded into out.
CHIP_ERROR DecodeValueIntoEmberBuffer(AttributeValueDecoder & decoder, const EmberAfAttributeMetadata * metadata,
MutableByteSpan & out)
{
VerifyOrReturnError(metadata != nullptr, CHIP_ERROR_INVALID_ARGUMENT);

const bool isNullable = metadata->IsNullable();

switch (AttributeBaseType(metadata->attributeType))
{
case ZCL_BOOLEAN_ATTRIBUTE_TYPE: // Boolean
return DecodeIntoEmberBuffer<bool>(decoder, isNullable, out);
case ZCL_INT8U_ATTRIBUTE_TYPE: // Unsigned 8-bit integer
return DecodeIntoEmberBuffer<uint8_t>(decoder, isNullable, out);
case ZCL_INT16U_ATTRIBUTE_TYPE: // Unsigned 16-bit integer
return DecodeIntoEmberBuffer<uint16_t>(decoder, isNullable, out);
case ZCL_INT24U_ATTRIBUTE_TYPE: // Unsigned 24-bit integer
return DecodeIntoEmberBuffer<OddSizedInteger<3, false>>(decoder, isNullable, out);
case ZCL_INT32U_ATTRIBUTE_TYPE: // Unsigned 32-bit integer
return DecodeIntoEmberBuffer<uint32_t>(decoder, isNullable, out);
case ZCL_INT40U_ATTRIBUTE_TYPE: // Unsigned 40-bit integer
return DecodeIntoEmberBuffer<OddSizedInteger<5, false>>(decoder, isNullable, out);
case ZCL_INT48U_ATTRIBUTE_TYPE: // Unsigned 48-bit integer
return DecodeIntoEmberBuffer<OddSizedInteger<6, false>>(decoder, isNullable, out);
case ZCL_INT56U_ATTRIBUTE_TYPE: // Unsigned 56-bit integer
return DecodeIntoEmberBuffer<OddSizedInteger<7, false>>(decoder, isNullable, out);
case ZCL_INT64U_ATTRIBUTE_TYPE: // Unsigned 64-bit integer
return DecodeIntoEmberBuffer<uint64_t>(decoder, isNullable, out);
case ZCL_INT8S_ATTRIBUTE_TYPE: // Signed 8-bit integer
return DecodeIntoEmberBuffer<int8_t>(decoder, isNullable, out);
case ZCL_INT16S_ATTRIBUTE_TYPE: // Signed 16-bit integer
return DecodeIntoEmberBuffer<int16_t>(decoder, isNullable, out);
case ZCL_INT24S_ATTRIBUTE_TYPE: // Signed 24-bit integer
return DecodeIntoEmberBuffer<OddSizedInteger<3, true>>(decoder, isNullable, out);
case ZCL_INT32S_ATTRIBUTE_TYPE: // Signed 32-bit integer
return DecodeIntoEmberBuffer<int32_t>(decoder, isNullable, out);
case ZCL_INT40S_ATTRIBUTE_TYPE: // Signed 40-bit integer
return DecodeIntoEmberBuffer<OddSizedInteger<5, true>>(decoder, isNullable, out);
case ZCL_INT48S_ATTRIBUTE_TYPE: // Signed 48-bit integer
return DecodeIntoEmberBuffer<OddSizedInteger<6, true>>(decoder, isNullable, out);
case ZCL_INT56S_ATTRIBUTE_TYPE: // Signed 56-bit integer
return DecodeIntoEmberBuffer<OddSizedInteger<7, true>>(decoder, isNullable, out);
case ZCL_INT64S_ATTRIBUTE_TYPE: // Signed 64-bit integer
return DecodeIntoEmberBuffer<int64_t>(decoder, isNullable, out);
case ZCL_SINGLE_ATTRIBUTE_TYPE: // 32-bit float
return DecodeIntoEmberBuffer<float>(decoder, isNullable, out);
case ZCL_DOUBLE_ATTRIBUTE_TYPE: // 64-bit float
return DecodeIntoEmberBuffer<double>(decoder, isNullable, out);
case ZCL_CHAR_STRING_ATTRIBUTE_TYPE: // Char string
return DecodeStringLikeIntoEmberBuffer<CharSpan, ShortPascalString>(decoder, isNullable, out);
case ZCL_LONG_CHAR_STRING_ATTRIBUTE_TYPE:
return DecodeStringLikeIntoEmberBuffer<CharSpan, LongPascalString>(decoder, isNullable, out);
case ZCL_OCTET_STRING_ATTRIBUTE_TYPE: // Octet string
return DecodeStringLikeIntoEmberBuffer<ByteSpan, ShortPascalString>(decoder, isNullable, out);
case ZCL_LONG_OCTET_STRING_ATTRIBUTE_TYPE:
return DecodeStringLikeIntoEmberBuffer<ByteSpan, LongPascalString>(decoder, isNullable, out);
default:
ChipLogError(DataManagement, "Attribute type 0x%x not handled", static_cast<int>(metadata->attributeType));
return CHIP_IM_GLOBAL_STATUS(Failure);
}
}

} // namespace

DataModel::ActionReturnStatus CodegenDataModelProvider::WriteAttribute(const DataModel::WriteAttributeRequest & request,
Expand Down Expand Up @@ -414,7 +223,10 @@ DataModel::ActionReturnStatus CodegenDataModelProvider::WriteAttribute(const Dat
}

MutableByteSpan dataBuffer = gEmberAttributeIOBufferSpan;
ReturnErrorOnFailure(DecodeValueIntoEmberBuffer(decoder, *attributeMetadata, dataBuffer));
{
Ember::EmberAttributeDataBuffer emberData(*attributeMetadata, dataBuffer);
ReturnErrorOnFailure(decoder.Decode(emberData));
}

Protocols::InteractionModel::Status status;

Expand Down
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