micropython/py/vstr.c

354 lines
9.5 KiB
C

/*
* This file is part of the Micro Python project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2013, 2014 Damien P. George
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#include <assert.h>
#include "py/mpconfig.h"
#include "py/misc.h"
// returned value is always at least 1 greater than argument
#define ROUND_ALLOC(a) (((a) & ((~0) - 7)) + 8)
// Init the vstr so it allocs exactly given number of bytes. Set length to zero.
void vstr_init(vstr_t *vstr, size_t alloc) {
if (alloc < 1) {
alloc = 1;
}
vstr->alloc = alloc;
vstr->len = 0;
vstr->buf = m_new(char, vstr->alloc);
if (vstr->buf == NULL) {
vstr->had_error = true;
return;
}
vstr->had_error = false;
vstr->fixed_buf = false;
}
// Init the vstr so it allocs exactly enough ram to hold given length, and set the length.
void vstr_init_len(vstr_t *vstr, size_t len) {
vstr_init(vstr, len);
vstr->len = len;
}
void vstr_init_fixed_buf(vstr_t *vstr, size_t alloc, char *buf) {
vstr->alloc = alloc;
vstr->len = 0;
vstr->buf = buf;
vstr->had_error = false;
vstr->fixed_buf = true;
}
void vstr_clear(vstr_t *vstr) {
if (!vstr->fixed_buf) {
m_del(char, vstr->buf, vstr->alloc);
}
vstr->buf = NULL;
}
vstr_t *vstr_new(void) {
vstr_t *vstr = m_new_obj(vstr_t);
if (vstr == NULL) {
return NULL;
}
vstr_init(vstr, 16);
return vstr;
}
vstr_t *vstr_new_size(size_t alloc) {
vstr_t *vstr = m_new_obj(vstr_t);
if (vstr == NULL) {
return NULL;
}
vstr_init(vstr, alloc);
return vstr;
}
void vstr_free(vstr_t *vstr) {
if (vstr != NULL) {
if (!vstr->fixed_buf) {
m_del(char, vstr->buf, vstr->alloc);
}
m_del_obj(vstr_t, vstr);
}
}
void vstr_reset(vstr_t *vstr) {
vstr->len = 0;
vstr->had_error = false;
}
bool vstr_had_error(vstr_t *vstr) {
return vstr->had_error;
}
char *vstr_str(vstr_t *vstr) {
if (vstr->had_error) {
return NULL;
}
return vstr->buf;
}
size_t vstr_len(vstr_t *vstr) {
if (vstr->had_error) {
return 0;
}
return vstr->len;
}
// Extend vstr strictly by requested size, return pointer to newly added chunk.
char *vstr_extend(vstr_t *vstr, size_t size) {
if (vstr->fixed_buf) {
return NULL;
}
char *new_buf = m_renew(char, vstr->buf, vstr->alloc, vstr->alloc + size);
if (new_buf == NULL) {
vstr->had_error = true;
return NULL;
}
char *p = new_buf + vstr->alloc;
vstr->alloc += size;
vstr->buf = new_buf;
return p;
}
STATIC bool vstr_ensure_extra(vstr_t *vstr, size_t size) {
if (vstr->len + size > vstr->alloc) {
if (vstr->fixed_buf) {
return false;
}
size_t new_alloc = ROUND_ALLOC((vstr->len + size) * 2);
char *new_buf = m_renew(char, vstr->buf, vstr->alloc, new_alloc);
if (new_buf == NULL) {
vstr->had_error = true;
return false;
}
vstr->alloc = new_alloc;
vstr->buf = new_buf;
}
return true;
}
void vstr_hint_size(vstr_t *vstr, size_t size) {
// it's not an error if we fail to allocate for the size hint
bool er = vstr->had_error;
vstr_ensure_extra(vstr, size);
vstr->had_error = er;
}
char *vstr_add_len(vstr_t *vstr, size_t len) {
if (vstr->had_error || !vstr_ensure_extra(vstr, len)) {
return NULL;
}
char *buf = vstr->buf + vstr->len;
vstr->len += len;
return buf;
}
// Doesn't increase len, just makes sure there is a null byte at the end
char *vstr_null_terminated_str(vstr_t *vstr) {
if (vstr->had_error || !vstr_ensure_extra(vstr, 1)) {
return NULL;
}
vstr->buf[vstr->len] = '\0';
return vstr->buf;
}
void vstr_add_byte(vstr_t *vstr, byte b) {
byte *buf = (byte*)vstr_add_len(vstr, 1);
if (buf == NULL) {
return;
}
buf[0] = b;
}
void vstr_add_char(vstr_t *vstr, unichar c) {
#if MICROPY_PY_BUILTINS_STR_UNICODE
// TODO: Can this be simplified and deduplicated?
// Is it worth just calling vstr_add_len(vstr, 4)?
if (c < 0x80) {
byte *buf = (byte*)vstr_add_len(vstr, 1);
if (buf == NULL) {
return;
}
*buf = (byte)c;
} else if (c < 0x800) {
byte *buf = (byte*)vstr_add_len(vstr, 2);
if (buf == NULL) {
return;
}
buf[0] = (c >> 6) | 0xC0;
buf[1] = (c & 0x3F) | 0x80;
} else if (c < 0x10000) {
byte *buf = (byte*)vstr_add_len(vstr, 3);
if (buf == NULL) {
return;
}
buf[0] = (c >> 12) | 0xE0;
buf[1] = ((c >> 6) & 0x3F) | 0x80;
buf[2] = (c & 0x3F) | 0x80;
} else {
assert(c < 0x110000);
byte *buf = (byte*)vstr_add_len(vstr, 4);
if (buf == NULL) {
return;
}
buf[0] = (c >> 18) | 0xF0;
buf[1] = ((c >> 12) & 0x3F) | 0x80;
buf[2] = ((c >> 6) & 0x3F) | 0x80;
buf[3] = (c & 0x3F) | 0x80;
}
#else
vstr_add_byte(vstr, c);
#endif
}
void vstr_add_str(vstr_t *vstr, const char *str) {
vstr_add_strn(vstr, str, strlen(str));
}
void vstr_add_strn(vstr_t *vstr, const char *str, size_t len) {
if (vstr->had_error || !vstr_ensure_extra(vstr, len)) {
// if buf is fixed, we got here because there isn't enough room left
// so just try to copy as much as we can, with room for a possible null byte
if (vstr->fixed_buf && vstr->len + 1 < vstr->alloc) {
len = vstr->alloc - vstr->len - 1;
goto copy;
}
return;
}
copy:
memmove(vstr->buf + vstr->len, str, len);
vstr->len += len;
}
STATIC char *vstr_ins_blank_bytes(vstr_t *vstr, size_t byte_pos, size_t byte_len) {
if (vstr->had_error) {
return NULL;
}
size_t l = vstr->len;
if (byte_pos > l) {
byte_pos = l;
}
if (byte_len > 0) {
// ensure room for the new bytes
if (!vstr_ensure_extra(vstr, byte_len)) {
return NULL;
}
// copy up the string to make room for the new bytes
memmove(vstr->buf + byte_pos + byte_len, vstr->buf + byte_pos, l - byte_pos);
// increase the length
vstr->len += byte_len;
}
return vstr->buf + byte_pos;
}
void vstr_ins_byte(vstr_t *vstr, size_t byte_pos, byte b) {
char *s = vstr_ins_blank_bytes(vstr, byte_pos, 1);
if (s != NULL) {
*s = b;
}
}
void vstr_ins_char(vstr_t *vstr, size_t char_pos, unichar chr) {
// TODO UNICODE
char *s = vstr_ins_blank_bytes(vstr, char_pos, 1);
if (s != NULL) {
*s = chr;
}
}
void vstr_cut_head_bytes(vstr_t *vstr, size_t bytes_to_cut) {
vstr_cut_out_bytes(vstr, 0, bytes_to_cut);
}
void vstr_cut_tail_bytes(vstr_t *vstr, size_t len) {
if (vstr->had_error) {
return;
}
if (len > vstr->len) {
vstr->len = 0;
} else {
vstr->len -= len;
}
}
void vstr_cut_out_bytes(vstr_t *vstr, size_t byte_pos, size_t bytes_to_cut) {
if (vstr->had_error || byte_pos >= vstr->len) {
return;
} else if (byte_pos + bytes_to_cut >= vstr->len) {
vstr->len = byte_pos;
} else {
memmove(vstr->buf + byte_pos, vstr->buf + byte_pos + bytes_to_cut, vstr->len - byte_pos - bytes_to_cut);
vstr->len -= bytes_to_cut;
}
}
void vstr_printf(vstr_t *vstr, const char *fmt, ...) {
va_list ap;
va_start(ap, fmt);
vstr_vprintf(vstr, fmt, ap);
va_end(ap);
}
void vstr_vprintf(vstr_t *vstr, const char *fmt, va_list ap) {
if (vstr->had_error || !vstr_ensure_extra(vstr, strlen(fmt))) {
return;
}
while (1) {
// try to print in the allocated space
// need to make a copy of the va_list because we may call vsnprintf multiple times
size_t size = vstr->alloc - vstr->len;
va_list ap2;
va_copy(ap2, ap);
int n = vsnprintf(vstr->buf + vstr->len, size, fmt, ap2);
va_end(ap2);
// if that worked, return
if (n > -1 && (size_t)n < size) {
vstr->len += n;
return;
}
// else try again with more space
if (n > -1) { // glibc 2.1
// n + 1 is precisely what is needed
if (!vstr_ensure_extra(vstr, n + 1)) {
return;
}
} else { // glibc 2.0
// increase to twice the old size
if (!vstr_ensure_extra(vstr, size * 2)) {
return;
}
}
}
}