#ifndef TOKU_SUB_BLOCK_H
#define TOKU_SUB_BLOCK_H

#ident "$Id$"
#ident "Copyright (c) 2007-2010 Tokutek Inc.  All rights reserved."
#ident "The technology is licensed by the Massachusetts Institute of Technology, Rutgers State University of New Jersey, and the Research Foundation of State University of New York at Stony Brook under United States of America Serial No. 11/760379 and to the patents and/or patent applications resulting from it."

#if defined(__cplusplus) || defined(__cilkplusplus)
extern "C" {
#endif

static const int max_sub_blocks = 8;
static const int target_sub_block_size = 512*1024;

struct sub_block {
    void *uncompressed_ptr;
    u_int32_t uncompressed_size;

    void *compressed_ptr;
    u_int32_t compressed_size;         // real compressed size
    u_int32_t compressed_size_bound;   // estimated compressed size

    u_int32_t xsum;                    // sub block checksum
};

struct stored_sub_block {
    u_int32_t uncompressed_size;
    u_int32_t compressed_size;
    u_int32_t xsum;
};

void 
sub_block_init(struct sub_block *sub_block);

// get the size of the compression header
size_t 
sub_block_header_size(int n_sub_blocks);

// get the sum of the sub block compressed sizes 
size_t 
get_sum_compressed_size_bound(int n_sub_blocks, struct sub_block sub_block[]);

// get the sum of the sub block uncompressed sizes 
size_t 
get_sum_uncompressed_size(int n_sub_blocks, struct sub_block sub_block[]);

// Choose n_sub_blocks and sub_block_size such that the product is >= total_size and the sub_block_size is at
// least >= the target_sub_block_size.
int
choose_sub_block_size(int total_size, int n_sub_blocks_limit, int *sub_block_size_ret, int *n_sub_blocks_ret);

void
set_all_sub_block_sizes(int total_size, int sub_block_size, int n_sub_blocks, struct sub_block sub_block[]);

// find the index of the first sub block that contains the offset
// Returns the index if found, else returns -1
int
get_sub_block_index(int n_sub_blocks, struct sub_block sub_block[], size_t offset);

#include "workset.h"

struct compress_work {
    struct work base;
    struct sub_block *sub_block;
};

void
compress_work_init(struct compress_work *w, struct sub_block *sub_block);

void
compress_sub_block(struct sub_block *sub_block);

void *
compress_worker(void *arg);

size_t
compress_all_sub_blocks(int n_sub_blocks, struct sub_block sub_block[], char *uncompressed_ptr, char *compressed_ptr, int num_cores);

struct decompress_work {
    struct work base;
    void *compress_ptr;
    void *uncompress_ptr;
    u_int32_t compress_size;
    u_int32_t uncompress_size;
    u_int32_t xsum;
    int error;
};

// initialize the decompression work
void 
decompress_work_init(struct decompress_work *dw,
                     void *compress_ptr, u_int32_t compress_size,
                     void *uncompress_ptr, u_int32_t uncompress_size,
                     u_int32_t xsum);

// decompress one block
int
decompress_sub_block(void *compress_ptr, u_int32_t compress_size, void *uncompress_ptr, u_int32_t uncompress_size, u_int32_t expected_xsum);

// decompress blocks until there is no more work to do
void *
decompress_worker(void *arg);

// decompress all sub blocks from the compressed_data buffer to the uncompressed_data buffer
// Returns 0 if success, otherwise an error
int
decompress_all_sub_blocks(int n_sub_blocks, struct sub_block sub_block[], unsigned char *compressed_data, unsigned char *uncompressed_data, int num_cores);

#if defined(__cplusplus) || defined(__cilkplusplus)
};
#endif

#endif
