This is the internal module for creating and handling "dynamic buffers". This means buffers that can be appended to, dynamically and grow to adapt.
There is always a terminating zero put at the end of the dynamic buffer.
The struct dynbuf
is used to hold data for each instance of a dynamic
buffer. The members of that struct MUST NOT be accessed or modified
without using the dedicated dynbuf API.
void Curl_dyn_init(struct dynbuf *s, size_t toobig);
This initializes a struct to use for dynbuf and it cannot fail. The toobig
value must be set to the maximum size we allow this buffer instance to
grow to. The functions below return CURLE_OUT_OF_MEMORY
when hitting this
limit.
void Curl_dyn_free(struct dynbuf *s);
Free the associated memory and clean up. After a free, the dynbuf
struct can
be reused to start appending new data to.
CURLcode Curl_dyn_addn(struct dynbuf *s, const void *mem, size_t len);
Append arbitrary data of a given length to the end of the buffer.
If this function fails it calls Curl_dyn_free
on dynbuf
.
CURLcode Curl_dyn_add(struct dynbuf *s, const char *str);
Append a C string to the end of the buffer.
If this function fails it calls Curl_dyn_free
on dynbuf
.
CURLcode Curl_dyn_addf(struct dynbuf *s, const char *fmt, ...);
Append a printf()
-style string to the end of the buffer.
If this function fails it calls Curl_dyn_free
on dynbuf
.
CURLcode Curl_dyn_vaddf(struct dynbuf *s, const char *fmt, va_list ap);
Append a vprintf()
-style string to the end of the buffer.
If this function fails it calls Curl_dyn_free
on dynbuf
.
void Curl_dyn_reset(struct dynbuf *s);
Reset the buffer length, but leave the allocation.
CURLcode Curl_dyn_tail(struct dynbuf *s, size_t length);
Keep length
bytes of the buffer tail (the last length
bytes of the
buffer). The rest of the buffer is dropped. The specified length
must not be
larger than the buffer length. To instead keep the leading part, see
Curl_dyn_setlen()
.
char *Curl_dyn_ptr(const struct dynbuf *s);
Returns a char *
to the buffer if it has a length, otherwise may return
NULL. Since the buffer may be reallocated, this pointer should not be trusted
or used anymore after the next buffer manipulation call.
unsigned char *Curl_dyn_uptr(const struct dynbuf *s);
Returns an unsigned char *
to the buffer if it has a length, otherwise may
return NULL. Since the buffer may be reallocated, this pointer should not be
trusted or used anymore after the next buffer manipulation call.
size_t Curl_dyn_len(const struct dynbuf *s);
Returns the length of the buffer in bytes. Does not include the terminating zero byte.
CURLcode Curl_dyn_setlen(struct dynbuf *s, size_t len);
Sets the new shorter length of the buffer in number of bytes. Keeps the
leftmost set number of bytes, discards the rest. To instead keep the tail part
of the buffer, see Curl_dyn_tail()
.