StringChunk

class StringChunk(*args, **kwargs)

GStringChunk provides efficient storage of groups of strings

String chunks are used to store groups of strings. Memory is allocated in blocks, and as strings are added to the GStringChunk they are copied into the next free position in a block. When a block is full a new block is allocated.

When storing a large number of strings, string chunks are more efficient than using strdup since fewer calls to malloc() are needed, and less memory is wasted in memory allocation overheads.

By adding strings with insert_const it is also possible to remove duplicates.

To create a new GStringChunk use new.

To add strings to a GStringChunk use insert.

To add strings to a GStringChunk, but without duplicating strings which are already in the GStringChunk, use insert_const.

To free the entire GStringChunk use free. It is not possible to free individual strings.

Methods

class StringChunk

clear() → None

Frees all strings contained within the StringChunk. After calling clear() it is not safe to access any of the strings which were contained within it.

Added in version 2.14.

free() → None

Frees all memory allocated by the StringChunk. After calling free() it is not safe to access any of the strings which were contained within it.

insert(string: str) → str

Adds a copy of string to the StringChunk. It returns a pointer to the new copy of the string in the StringChunk. The characters in the string can be changed, if necessary, though you should not change anything after the end of the string.

Unlike insert_const(), this function does not check for duplicates. Also strings added with insert() will not be searched by insert_const() when looking for duplicates.

Parameters:

string – the string to add

insert_const(string: str) → str

Adds a copy of string to the StringChunk, unless the same string has already been added to the StringChunk with insert_const().

This function is useful if you need to copy a large number of strings but do not want to waste space storing duplicates. But you must remember that there may be several pointers to the same string, and so any changes made to the strings should be done very carefully.

Note that insert_const() will not return a pointer to a string added with insert(), even if they do match.

Parameters:

string – the string to add

insert_len(string: str, len: int) → str

Adds a copy of the first len bytes of string to the StringChunk. The copy is nul-terminated.

Since this function does not stop at nul bytes, it is the caller’s responsibility to ensure that string has at least len addressable bytes.

The characters in the returned string can be changed, if necessary, though you should not change anything after the end of the string.

Added in version 2.4.

Parameters:

• string – bytes to insert

• len – number of bytes of string to insert, or -1 to insert a nul-terminated string