Core.Bigbuffer
SourceExtensible string buffers based on Bigstrings.
This module implements string buffers that automatically expand as necessary. It provides accumulative concatenation of strings in quasi-linear time (instead of quadratic time when strings are concatenated pairwise).
This implementation uses Bigstrings instead of strings. This removes the 16MB limit on buffer size (on 32-bit machines), and improves I/O-performance when reading/writing from/to channels.
include Base.Buffer.S
The abstract type of buffers.
create n
returns a fresh buffer, initially empty. The n
parameter is the initial size of the internal storage medium that holds the buffer contents. That storage is automatically reallocated when more than n
characters are stored in the buffer, but shrinks back to n
characters when reset
is called.
For best performance, n
should be of the same order of magnitude as the number of characters that are expected to be stored in the buffer (for instance, 80 for a buffer that holds one output line). Nothing bad will happen if the buffer grows beyond that limit, however. In doubt, take n = 16
for instance.
Return a copy of the current contents of the buffer. The buffer itself is unchanged.
blit ~src ~src_pos ~dst ~dst_pos ~len
copies len
characters from the current contents of the buffer src
, starting at offset src_pos
to bytes dst
, starting at character dst_pos
.
Raises Invalid_argument
if src_pos
and len
do not designate a valid substring of src
, or if dst_pos
and len
do not designate a valid substring of dst
.
include Base.Blit.S_distinct with type src := t with type dst := bytes
Gets the (zero-based) n-th character of the buffer. Raises Invalid_argument
if index out of bounds.
Empties the buffer and deallocates the internal storage holding the buffer contents, replacing it with the initial internal storage of length n
that was allocated by create n
. For long-lived buffers that may have grown a lot, reset
allows faster reclamation of the space used by the buffer.
add_char b c
appends the character c
at the end of the buffer b
.
add_string b s
appends the string s
at the end of the buffer b
.
add_substring b s pos len
takes len
characters from offset pos
in string s
and appends them at the end of the buffer b
.
add_bytes b s
appends the bytes s
at the end of the buffer b
.
add_subbytes b s pos len
takes len
characters from offset pos
in bytes s
and appends them at the end of the buffer b
.
Return a copy of the current contents of the buffer as a bigstring. The buffer itself is unchanged.
Return the actual underlying bigstring used by this bigbuffer. No copying is involved. To be safe, use and finish with the returned value before calling any other function in this module on the same Bigbuffer.t
.
add_bigstring b s
appends the bigstring s
at the end of the buffer b
.
add_bin_prot b writer x
appends the bin-protted representation of x
at the end of the buffer b
.
add_substitute b f s
appends the string pattern s
at the end of the buffer b
with substitution. The substitution process looks for variables into the pattern and substitutes each variable name by its value, as obtained by applying the mapping f
to the variable name. Inside the string pattern, a variable name immediately follows a non-escaped $
character and is one of the following:
_
characters,An escaped $
character is a $
that immediately follows a backslash character; it then stands for a plain $
. Raise Caml.Not_found
or Not_found_s
if the closing character of a parenthesized variable cannot be found.