root/crypto/openssl/crypto/comp/comp_local.h
/*
 * Copyright 2015-2016 The OpenSSL Project Authors. All Rights Reserved.
 *
 * Licensed under the Apache License 2.0 (the "License").  You may not use
 * this file except in compliance with the License.  You can obtain a copy
 * in the file LICENSE in the source distribution or at
 * https://www.openssl.org/source/license.html
 */

struct comp_method_st {
    int type; /* NID for compression library */
    const char *name; /* A text string to identify the library */
    int (*init)(COMP_CTX *ctx);
    void (*finish)(COMP_CTX *ctx);
    ossl_ssize_t (*compress)(COMP_CTX *ctx,
        unsigned char *out, size_t olen,
        unsigned char *in, size_t ilen);
    ossl_ssize_t (*expand)(COMP_CTX *ctx,
        unsigned char *out, size_t olen,
        unsigned char *in, size_t ilen);
};

struct comp_ctx_st {
    struct comp_method_st *meth;
    unsigned long compress_in;
    unsigned long compress_out;
    unsigned long expand_in;
    unsigned long expand_out;
    void *data;
};