Read Shard format

The Read Shard has the following structure:

• bytes [0, SHARD_OFFSET_MAGIC[: The shard magic

• bytes [SHARD_OFFSET_MAGIC, objects_position[: The header (shard_header_t)

• bytes [objects_position, index_position[: objects_count times the size of the object (u_int64_t) followed by the content of the object

• bytes [index_position, hash_position[: An array of index entries. The size of the array is provided by cmph_size after building the hash function. An index entry is made of the key (of SHARD_KEY_LEN bytes) and the object position (u_int64_t) in the range [objects_position, index_position[. If the object position is UINT64_MAX, this means the object has been deleted.

• bytes [hash_position, …[: The hash function, as written by cmph_dump