Buffer Move Semantics

[flatcap]

Now that Buffers are starting to take off, it's time to use them more efficiently.

There are ~40 buf_copy()s and ~200 buf_strcpy()s, where an existing string is copied.
Many of these source strings are just freed afterwards.

Following navi's ideas on IRC, how about:

// Free dest's contents and move src's in, leaving src empty
void buf_move(struct Buffer *dest, struct Buffer *src);

// Free dest's contents and move the string, setting the string ptr to NULL
void buf_move_str(struct Buffer *buf_dest, const char **ptr);

In buf_move_str(), the dest Buffer needs to know the length of the allocation.
Using strlen() would be good enough.

Alternatively, we could add a int len param.
If we know then length, pass it, if not pass -1 and use strlen() in the function.

Another possibly useful function is:

// Swap the contents of first and second
void buf_swap(struct Buffer *first, struct Buffer *second);

Care would be needed when dealing with the BufferPool.

[roccoblues]

Alternatively, we could add a int len param.
If we know then length, pass it, if not pass -1 and use strlen() in the function.

I like the explicitness of having two functions:

void buf_move_str(struct Buffer *buf_dest, const char **ptr);
void buf_move_str_n(struct Buffer *buf_dest, const char **ptr, size_t len);