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()).

1 files changed, 5 insertions, 1 deletions

diff --git a/py/misc.h b/py/misc.h
index 1bf4d8f291..2d6fb978ac 100644
--- a/py/misc.h
+++ b/py/misc.h
@@ -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);