CRC32.cpp

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// ======================================================================
// \title  CRC32.cpp
// \author dinkel
// \brief  cpp file for CRC32 implementation of Hash class
//
// \copyright
// Copyright 2009-2015, by the California Institute of Technology.
// ALL RIGHTS RESERVED.  United States Government Sponsorship
// acknowledged.
//
// ======================================================================

#include <Utils/Hash/Hash.hpp>

static_assert(sizeof(unsigned long) >= sizeof(U32), "CRC32 cannot fit in CRC32 library chosen types");

namespace Utils {

Hash ::Hash() {
    this->init();
}

Hash ::~Hash() {}

void Hash ::hash(const void* const data, const FwSizeType len, HashBuffer& buffer) {
    HASH_HANDLE_TYPE local_hash_handle;
    local_hash_handle = 0xffffffffL;
    FW_ASSERT(data);
    char c;
    for (FwSizeType index = 0; index < len; index++) {
        c = static_cast<const char*>(data)[index];
        local_hash_handle = static_cast<HASH_HANDLE_TYPE>(update_crc_32(local_hash_handle, c));
    }
    HashBuffer bufferOut;
    // For CRC32 we need to return the one's complement of the result:
    Fw::SerializeStatus status = bufferOut.serializeFrom(~(local_hash_handle));
    FW_ASSERT(Fw::FW_SERIALIZE_OK == status);
    buffer = bufferOut;
}

void Hash ::init() {
    this->hash_handle = 0xffffffffL;
}

void Hash ::update(const void* const data, FwSizeType len) {
    FW_ASSERT(data);
    char c;
    for (FwSizeType index = 0; index < len; index++) {
        c = static_cast<const char*>(data)[index];
        this->hash_handle = static_cast<HASH_HANDLE_TYPE>(update_crc_32(this->hash_handle, c));
    }
}

void Hash ::final(HashBuffer& buffer) {
    HashBuffer bufferOut;
    // For CRC32 we need to return the one's complement of the result:
    Fw::SerializeStatus status = bufferOut.serializeFrom(~(this->hash_handle));
    FW_ASSERT(Fw::FW_SERIALIZE_OK == status);
    buffer = bufferOut;
}

void Hash ::final(U32& hashvalue) {
    FW_ASSERT(sizeof(this->hash_handle) == sizeof(U32));
    // For CRC32 we need to return the one's complement of the result:
    hashvalue = ~(this->hash_handle);
}

void Hash ::setHashValue(HashBuffer& value) {
    Fw::SerializeStatus status = value.deserializeTo(this->hash_handle);
    FW_ASSERT(Fw::FW_SERIALIZE_OK == status);
    // Expecting `value` to already be one's complement; so doing one's complement
    // here for correct hash updates
    this->hash_handle = ~this->hash_handle;
}
}  // namespace Utils