Commit 5d2499c6 authored by Paul Sokolovsky's avatar Paul Sokolovsky
Browse files

Add "buffer management" and "shrink" API calls to vstr.

vstr is initially intended to deal with arbitrary-length strings. By
providing a bit lower-level API calls, it will be also useful to deal
with arbitrary-length I/O buffers (the difference from strings is that
buffers are filled from "outside", via I/O).

Another issue, especially aggravated by I/O buffer use, is alloc size
vs actual size length. If allocated 1Mb for buffer, but actually
read 1 byte, we don't want to keep rest of 1Mb be locked by this I/O
result, but rather return it to heap ASAP ("shrink" buffer before passing
it to qstr_from_str_take()).
parent ca318bba
......@@ -614,7 +614,7 @@ mp_lexer_t *mp_lexer_new(const char *src_name, void *stream_data, mp_lexer_strea
lex->num_indent_level = 1;
lex->indent_level = m_new(uint16_t, lex->alloc_indent_level);
lex->indent_level[0] = 0;
vstr_init(&lex->vstr);
vstr_init(&lex->vstr, 32);
// preload characters
lex->chr0 = stream_next_char(stream_data);
......
......@@ -58,15 +58,19 @@ typedef struct _vstr_t {
bool had_error;
} vstr_t;
void vstr_init(vstr_t *vstr);
void vstr_init(vstr_t *vstr, int alloc);
void vstr_clear(vstr_t *vstr);
vstr_t *vstr_new(void);
vstr_t *vstr_new_size(int alloc);
void vstr_free(vstr_t *vstr);
void vstr_reset(vstr_t *vstr);
bool vstr_had_error(vstr_t *vstr);
char *vstr_str(vstr_t *vstr);
int vstr_len(vstr_t *vstr);
void vstr_hint_size(vstr_t *vstr, int size);
char *vstr_extend(vstr_t *vstr, int size);
bool vstr_set_size(vstr_t *vstr, int size);
bool vstr_shrink(vstr_t *vstr);
char *vstr_add_len(vstr_t *vstr, int len);
void vstr_add_byte(vstr_t *vstr, byte v);
void vstr_add_char(vstr_t *vstr, unichar chr);
......
......@@ -6,8 +6,8 @@
// returned value is always at least 1 greater than argument
#define ROUND_ALLOC(a) (((a) & ((~0) - 7)) + 8)
void vstr_init(vstr_t *vstr) {
vstr->alloc = 32;
void vstr_init(vstr_t *vstr, int alloc) {
vstr->alloc = alloc;
vstr->len = 0;
vstr->buf = m_new(char, vstr->alloc);
if (vstr->buf == NULL) {
......@@ -28,7 +28,16 @@ vstr_t *vstr_new(void) {
if (vstr == NULL) {
return NULL;
}
vstr_init(vstr);
vstr_init(vstr, 32);
return vstr;
}
vstr_t *vstr_new_size(int alloc) {
vstr_t *vstr = m_new(vstr_t, 1);
if (vstr == NULL) {
return NULL;
}
vstr_init(vstr, alloc);
return vstr;
}
......@@ -63,6 +72,36 @@ int vstr_len(vstr_t *vstr) {
return vstr->len;
}
// Extend vstr strictly to by requested size, return pointer to newly added chunk
char *vstr_extend(vstr_t *vstr, int size) {
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;
}
// Shrink vstr to be given size
bool vstr_set_size(vstr_t *vstr, int size) {
char *new_buf = m_renew(char, vstr->buf, vstr->alloc, size);
if (new_buf == NULL) {
vstr->had_error = true;
return false;
}
vstr->buf = new_buf;
vstr->alloc = vstr->len = size;
return true;
}
// Shrink vstr allocation to its actual length
bool vstr_shrink(vstr_t *vstr) {
return vstr_set_size(vstr, vstr->len);
}
bool vstr_ensure_extra(vstr_t *vstr, int size) {
if (vstr->len + size + 1 > vstr->alloc) {
int new_alloc = ROUND_ALLOC((vstr->len + size + 1) * 2);
......
......@@ -390,7 +390,7 @@ void do_repl(void) {
stdout_tx_str("Type \"help()\" for more information.\r\n");
vstr_t line;
vstr_init(&line);
vstr_init(&line, 32);
for (;;) {
vstr_reset(&line);
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment