py: Add comments for vstr_init and mp_obj_new_str.

This commit is contained in:
Damien George 2015-01-21 23:08:36 +00:00
parent 05005f679e
commit 77089bebd4
2 changed files with 9 additions and 0 deletions

View File

@ -1856,6 +1856,8 @@ const mp_obj_type_t mp_type_bytes = {
// the zero-length bytes
const mp_obj_str_t mp_const_empty_bytes_obj = {{&mp_type_bytes}, 0, 0, NULL};
// Create a str/bytes object using the given data. New memory is allocated and
// the data is copied across.
mp_obj_t mp_obj_new_str_of_type(const mp_obj_type_t *type, const byte* data, mp_uint_t len) {
mp_obj_str_t *o = m_new_obj(mp_obj_str_t);
o->base.type = type;
@ -1870,6 +1872,9 @@ mp_obj_t mp_obj_new_str_of_type(const mp_obj_type_t *type, const byte* data, mp_
return o;
}
// Create a str/bytes object from the given vstr. The vstr buffer is resized to
// the exact length required and then reused for the str/bytes object. The vstr
// is cleared and can safely be passed to vstr_free if it was heap allocated.
mp_obj_t mp_obj_new_str_from_vstr(const mp_obj_type_t *type, vstr_t *vstr) {
// if not a bytes object, look if a qstr with this data already exists
if (type == &mp_type_str) {

View File

@ -35,6 +35,8 @@
// 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.
// Length is set to zero, and null byte written in first position.
void vstr_init(vstr_t *vstr, size_t alloc) {
if (alloc < 2) {
// need at least 1 byte for the null byte at the end
@ -52,6 +54,8 @@ void vstr_init(vstr_t *vstr, size_t alloc) {
vstr->fixed_buf = false;
}
// Init the vstr so it allocs exactly enough ram to hold given length (plus the
// null terminating byte), set the length, and write the null byte at the end.
void vstr_init_len(vstr_t *vstr, size_t len) {
vstr_init(vstr, len + 1);
vstr_add_len(vstr, len);