git/reftable/basics.h

/*
Copyright 2020 Google LLC

Use of this source code is governed by a BSD-style
license that can be found in the LICENSE file or at
https://developers.google.com/open-source/licenses/bsd
*/

#ifndef BASICS_H
#define BASICS_H

/*
 * miscellaneous utilities that are not provided by Git.
 */

#include "system.h"
#include "reftable-basics.h"

/* Bigendian en/decoding of integers */

void put_be24(uint8_t *out, uint32_t i);
uint32_t get_be24(uint8_t *in);
void put_be16(uint8_t *out, uint16_t i);

/*
 * find smallest index i in [0, sz) at which `f(i) > 0`, assuming that f is
 * ascending. Return sz if `f(i) == 0` for all indices. The search is aborted
 * and `sz` is returned in case `f(i) < 0`.
 *
 * Contrary to bsearch(3), this returns something useful if the argument is not
 * found.
 */
size_t binsearch(size_t sz, int (*f)(size_t k, void *args), void *args);

/*
 * Frees a NULL terminated array of malloced strings. The array itself is also
 * freed.
 */
void free_names(char **a);

/*
 * Parse a newline separated list of names. `size` is the length of the buffer,
 * without terminating '\0'. Empty names are discarded. Returns a `NULL`
 * pointer when allocations fail.
 */
char **parse_names(char *buf, int size);

/* compares two NULL-terminated arrays of strings. */
int names_equal(const char **a, const char **b);

/* returns the array size of a NULL-terminated array of strings. */
size_t names_length(const char **names);

/* Allocation routines; they invoke the functions set through
 * reftable_set_alloc() */
void *reftable_malloc(size_t sz);
void *reftable_realloc(void *p, size_t sz);
void reftable_free(void *p);
void *reftable_calloc(size_t nelem, size_t elsize);
char *reftable_strdup(const char *str);

#define REFTABLE_ALLOC_ARRAY(x, alloc) …
#define REFTABLE_CALLOC_ARRAY(x, alloc) …
#define REFTABLE_REALLOC_ARRAY(x, alloc) …
#define REFTABLE_ALLOC_GROW(x, nr, alloc) …
#define REFTABLE_FREE_AND_NULL(p) …

#ifndef REFTABLE_ALLOW_BANNED_ALLOCATORS
#define REFTABLE_BANNED(func) …
# undef malloc
#define malloc(sz) …
# undef realloc
#define realloc(ptr, sz) …
# undef free
#define free(ptr) …
# undef calloc
#define calloc(nelem, elsize) …
# undef strdup
#define strdup(str) …
#endif

/* Find the longest shared prefix size of `a` and `b` */
struct strbuf;
int common_prefix_size(struct strbuf *a, struct strbuf *b);

int hash_size(uint32_t id);

#endif