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()).
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@ -614,7 +614,7 @@ mp_lexer_t *mp_lexer_new(const char *src_name, void *stream_data, mp_lexer_strea
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lex->num_indent_level = 1;
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lex->indent_level = m_new(uint16_t, lex->alloc_indent_level);
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lex->indent_level[0] = 0;
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vstr_init(&lex->vstr);
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vstr_init(&lex->vstr, 32);
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// preload characters
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lex->chr0 = stream_next_char(stream_data);
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@ -58,15 +58,19 @@ typedef struct _vstr_t {
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bool had_error;
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} vstr_t;
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void vstr_init(vstr_t *vstr);
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void vstr_init(vstr_t *vstr, int alloc);
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void vstr_clear(vstr_t *vstr);
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vstr_t *vstr_new(void);
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vstr_t *vstr_new_size(int alloc);
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void vstr_free(vstr_t *vstr);
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void vstr_reset(vstr_t *vstr);
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bool vstr_had_error(vstr_t *vstr);
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char *vstr_str(vstr_t *vstr);
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int vstr_len(vstr_t *vstr);
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void vstr_hint_size(vstr_t *vstr, int size);
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char *vstr_extend(vstr_t *vstr, int size);
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bool vstr_set_size(vstr_t *vstr, int size);
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bool vstr_shrink(vstr_t *vstr);
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char *vstr_add_len(vstr_t *vstr, int len);
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void vstr_add_byte(vstr_t *vstr, byte v);
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void vstr_add_char(vstr_t *vstr, unichar chr);
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45
py/vstr.c
45
py/vstr.c
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@ -6,8 +6,8 @@
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// returned value is always at least 1 greater than argument
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#define ROUND_ALLOC(a) (((a) & ((~0) - 7)) + 8)
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void vstr_init(vstr_t *vstr) {
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vstr->alloc = 32;
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void vstr_init(vstr_t *vstr, int alloc) {
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vstr->alloc = alloc;
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vstr->len = 0;
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vstr->buf = m_new(char, vstr->alloc);
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if (vstr->buf == NULL) {
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@ -28,7 +28,16 @@ vstr_t *vstr_new(void) {
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if (vstr == NULL) {
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return NULL;
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}
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vstr_init(vstr);
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vstr_init(vstr, 32);
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return vstr;
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}
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vstr_t *vstr_new_size(int alloc) {
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vstr_t *vstr = m_new(vstr_t, 1);
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if (vstr == NULL) {
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return NULL;
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}
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vstr_init(vstr, alloc);
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return vstr;
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}
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@ -63,6 +72,36 @@ int vstr_len(vstr_t *vstr) {
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return vstr->len;
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}
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// Extend vstr strictly to by requested size, return pointer to newly added chunk
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char *vstr_extend(vstr_t *vstr, int size) {
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char *new_buf = m_renew(char, vstr->buf, vstr->alloc, vstr->alloc + size);
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if (new_buf == NULL) {
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vstr->had_error = true;
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return NULL;
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}
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char *p = new_buf + vstr->alloc;
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vstr->alloc += size;
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vstr->buf = new_buf;
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return p;
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}
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// Shrink vstr to be given size
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bool vstr_set_size(vstr_t *vstr, int size) {
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char *new_buf = m_renew(char, vstr->buf, vstr->alloc, size);
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if (new_buf == NULL) {
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vstr->had_error = true;
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return false;
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}
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vstr->buf = new_buf;
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vstr->alloc = vstr->len = size;
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return true;
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}
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// Shrink vstr allocation to its actual length
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bool vstr_shrink(vstr_t *vstr) {
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return vstr_set_size(vstr, vstr->len);
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}
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bool vstr_ensure_extra(vstr_t *vstr, int size) {
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if (vstr->len + size + 1 > vstr->alloc) {
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int new_alloc = ROUND_ALLOC((vstr->len + size + 1) * 2);
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@ -390,7 +390,7 @@ void do_repl(void) {
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stdout_tx_str("Type \"help()\" for more information.\r\n");
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vstr_t line;
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vstr_init(&line);
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vstr_init(&line, 32);
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for (;;) {
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vstr_reset(&line);
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