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#include <stdlib.h>

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#include <errno.h>

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#include "blob.hpp"

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#include <unistd.h>

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Blob::Blob(uint8_t *seedData, size_t seedLength)

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{

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    // Create a temporary file to store blob data

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    // not using tmpfile() because we need to know the filename

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    // for later renaming and avoid deletion on close

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    // Assume that a tmp directory exists in the current directory

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    uint8_t template_name[] = "tmp/blobXXXXXX";

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    int fd = mkstemp((char *)template_name);

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    if (fd == -1) {

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        throw errno;

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    }

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    // Open file for stdlib I/O

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    m_file = fdopen(fd, "w+");

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    if (m_file == NULL) {

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        throw errno;

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    }

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    // Save a copy of the filename

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    m_filename = (char *)template_name;

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    // Seed the MD5 hash with the seed data

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    md5.update(seedData, seedLength);

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}

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Blob::~Blob() {

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    if (m_file != NULL) {

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        std::fclose(m_file);

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        std::remove(m_filename.c_str());

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    }

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}

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MD5::digest_t Blob::digest() {

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    return md5.digest();

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}

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uint32_t Blob::appendChunk(uint8_t *data, size_t length) {

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    // Write data to file

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    if (std::fwrite(data, 1, length, m_file) != length) {

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        return errno;

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    }

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    // Update MD5 hash

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    md5.update(data, length);

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    return 0;

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}

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uint32_t Blob::asFile(std::filesystem::path &filename)

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{

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    // Flush file

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    if (std::fflush(m_file) != 0) {

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        return errno;

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    }

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    // Sync file to disk

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    if (fsync(fileno(m_file)) != 0) {

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        return errno;

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    }

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    // Close file

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    if (std::fclose(m_file) != 0) {

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        return errno;

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    }

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    m_file = NULL;

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    // Rename temp file to final file

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    if (std::rename(m_filename.c_str(), filename.c_str()) != 0) {

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        return errno;

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    }

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    return 0;

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}