Class: MTBL::Utils

Inherits:
Object
  • Object
show all
Defined in:
ext/mtbl/ruby-mtbl.c

Class Method Summary collapse

Class Method Details

.metadata(fname) ⇒ Object

Utils



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# File 'ext/mtbl/ruby-mtbl.c', line 480

static VALUE rbmtbl_utils_metadata(VALUE class, VALUE fname) {
    int fd, ret;
    struct stat ss;
    struct mtbl_reader *r;
    const struct mtbl_metadata *m;
    mtbl_compression_type compression_algorithm;
    uint64_t data_block_size, count_entries, count_data_blocks, bytes_data_blocks;
    uint64_t bytes_index_block, bytes_keys, bytes_values, index_block_offset;
    double p_data, p_index, compactness;
    VALUE metadata = rb_hash_new();

    if (TYPE(fname) != T_STRING) {
        rb_raise(rb_eArgError, "File name must be a string");
        return Qnil;
    }

    fd = open(StringValueCStr(fname), O_RDONLY);
    if (fd < 0) {
        rb_raise(rb_eRuntimeError, "Unable to open file %s: %s", StringValueCStr(fname), strerror(errno));
        return Qnil;
    }

    ret = fstat(fd, &ss);
    if (ret < 0) {
        close(fd);
        rb_raise(rb_eRuntimeError, "Failed fstat on file %s: %s", StringValueCStr(fname), strerror(errno));
        return Qnil;
    }

    r = mtbl_reader_init_fd(fd, NULL);
    if (r == NULL) {
        close(fd);
        rb_raise(rb_eRuntimeError, "Unable to open file %s: mtbl_reader_init_fd()", StringValueCStr(fname));
        return Qnil;
    }

    m = mtbl_reader_metadata(r);

    data_block_size = mtbl_metadata_data_block_size(m);
    compression_algorithm = mtbl_metadata_compression_algorithm(m);
    count_entries = mtbl_metadata_count_entries(m);
    count_data_blocks = mtbl_metadata_count_data_blocks(m);
    bytes_data_blocks = mtbl_metadata_bytes_data_blocks(m);
    bytes_index_block = mtbl_metadata_bytes_index_block(m);
    bytes_keys = mtbl_metadata_bytes_keys(m);
    bytes_values = mtbl_metadata_bytes_values(m);
    index_block_offset = mtbl_metadata_index_block_offset(m);
    p_data = 100.0 * bytes_data_blocks / ss.st_size;
    p_index = 100.0 * bytes_index_block / ss.st_size;
    compactness = 100.0 * ss.st_size / (bytes_keys + bytes_values);

    rb_hash_aset(metadata, ID2SYM(rb_intern_const("filename")), fname);
    rb_hash_aset(metadata, ID2SYM(rb_intern_const("filesize")), LL2NUM((size_t) ss.st_size));
    rb_hash_aset(metadata, ID2SYM(rb_intern_const("index_block_offset")), LL2NUM(index_block_offset));
    rb_hash_aset(metadata, ID2SYM(rb_intern_const("index_bytes")), LL2NUM(bytes_index_block));
    rb_hash_aset(metadata, ID2SYM(rb_intern_const("index_bytes_pct")), DBL2NUM(p_index));
    rb_hash_aset(metadata, ID2SYM(rb_intern_const("data_block_bytes")), LL2NUM(bytes_data_blocks));
    rb_hash_aset(metadata, ID2SYM(rb_intern_const("data_block_bytes_pct")), DBL2NUM(p_data));
    rb_hash_aset(metadata, ID2SYM(rb_intern_const("data_block_size")), LL2NUM(data_block_size));
    rb_hash_aset(metadata, ID2SYM(rb_intern_const("data_block_count")), LL2NUM(count_data_blocks));
    rb_hash_aset(metadata, ID2SYM(rb_intern_const("entry_count")), LL2NUM(count_entries));
    rb_hash_aset(metadata, ID2SYM(rb_intern_const("key_bytes")), LL2NUM(bytes_keys));
    rb_hash_aset(metadata, ID2SYM(rb_intern_const("value_bytes")), LL2NUM(bytes_values));
    rb_hash_aset(metadata, ID2SYM(rb_intern_const("compression_algorithm")), rb_str_new2(mtbl_compression_type_to_str(compression_algorithm)));
    rb_hash_aset(metadata, ID2SYM(rb_intern_const("compactness")), DBL2NUM(compactness));

    mtbl_reader_destroy(&r);
    close(fd);

    return metadata;
}