Class: ZstdNative::DStream

Inherits:
Object
  • Object
show all
Defined in:
ext/zstd_native/zstd_native.c

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Object 



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# File 'ext/zstd_native/zstd_native.c', line 484

static VALUE dstream_initialize(VALUE self) {
    ZSTD_DStream *stream = ZSTD_createDStream();
    if (!stream) {
        rb_raise(eZstdError, "Failed to create decompression stream");
    }

    size_t result = ZSTD_initDStream(stream);
    if (ZSTD_isError(result)) {
        ZSTD_freeDStream(stream);
        rb_raise(eZstdError, "Failed to initialize decompression stream: %s", ZSTD_getErrorName(result));
    }

    DATA_PTR(self) = stream;
    return self;
}

Class Method Details

.in_size ⇒ Object 



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# File 'ext/zstd_native/zstd_native.c', line 537

static VALUE dstream_in_size(VALUE self) {
    return SIZET2NUM(ZSTD_DStreamInSize());
}

.out_size ⇒ Object 



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# File 'ext/zstd_native/zstd_native.c', line 541

static VALUE dstream_out_size(VALUE self) {
    return SIZET2NUM(ZSTD_DStreamOutSize());
}

Instance Method Details

#decompress(data) ⇒ Object 



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# File 'ext/zstd_native/zstd_native.c', line 504

static VALUE dstream_decompress(VALUE self, VALUE data) {
    Check_Type(data, T_STRING);

    ZSTD_DStream *stream;
    TypedData_Get_Struct(self, ZSTD_DStream, &dstream_type, stream);

    const char *src = RSTRING_PTR(data);
    size_t src_size = RSTRING_LEN(data);

    ZSTD_inBuffer input = {src, src_size, 0};

    size_t out_capacity = ZSTD_DStreamOutSize();
    VALUE result = rb_str_buf_new(out_capacity);
    char *dst = RSTRING_PTR(result);
    size_t total_written = 0;

    while (input.pos < input.size) {
        ZSTD_outBuffer output = {dst + total_written, out_capacity - total_written, 0};
        size_t remaining = ZSTD_decompressStream(stream, &output, &input);
        check_zstd_error(remaining, "Stream decompression failed");
        total_written += output.pos;

        if (total_written >= out_capacity && input.pos < input.size) {
            out_capacity *= 2;
            rb_str_resize(result, out_capacity);
            dst = RSTRING_PTR(result);
        }
    }

    rb_str_set_len(result, total_written);
    return result;
}