sapling/eden/scm/lib/clib/buffer.h
Adam Simpkins ab3a7cb21f Move fb-mercurial sources into an eden/scm subdirectory.
Summary:
In preparation for merging fb-mercurial sources to the Eden repository,
move everything from the top-level directory into an `eden/scm`
subdirectory.
2019-11-13 16:04:48 -08:00

64 lines
1.7 KiB
C

// Copyright (c) 2004-present, Facebook, Inc.
// All Rights Reserved.
//
// This software may be used and distributed according to the terms of the
// GNU General Public License version 2 or any later version.
// buffer.c: declarations for a generic mechanism to expand a heap-allocated
// buffer. this is for internal use only.
// no-check-code
#ifndef FBHGEXT_CLIB_BUFFER_H
#define FBHGEXT_CLIB_BUFFER_H
#include <stdbool.h>
#include <stddef.h>
#include <stdlib.h>
static inline bool expand_to_fit(
void** buffer,
size_t num_slots_used,
size_t* num_slots_total,
size_t input_count,
size_t item_sz,
const float factor,
const size_t min_increment,
const size_t max_increment) {
size_t remaining = *num_slots_total - num_slots_used;
if (input_count > remaining) {
// need realloc
size_t new_slots_total = factor * ((float)*num_slots_total);
if (new_slots_total < min_increment + *num_slots_total) {
new_slots_total = min_increment + *num_slots_total;
}
if (new_slots_total > max_increment + *num_slots_total) {
new_slots_total = max_increment + *num_slots_total;
}
if (new_slots_total < input_count + *num_slots_total) {
new_slots_total = input_count + *num_slots_total;
}
void* newbuffer = realloc(*buffer, item_sz * new_slots_total);
if (newbuffer == NULL) {
return false;
}
*buffer = newbuffer;
*num_slots_total = new_slots_total;
}
return true;
}
extern bool buffer_append(
char** buffer,
size_t* buffer_idx,
size_t* buffer_sz,
char* input,
size_t input_sz,
const float factor,
const size_t min_increment,
const size_t max_increment);
#endif /* FBHGEXT_CLIB_BUFFER_H */