view mercurial/mpatch.h @ 49232:4c57ce494a4e

worker: stop relying on garbage collection to release memoryview

On CPython, before resizing the bytearray, all memoryviews referencing it must
be released. Before this change, we ensured that all references to them were
deleted. On CPython, this was enough to set the reference count to zero, which
results in garbage collecting and releasing them.

On PyPy, releasing the memoryviews is not necessary because they are implemented
differently. If it would be necessary however, ensuring that all references are
deleted would not be suffient because PyPy doesn’t use reference counting.

By using with statements that take care of releasing the memoryviews, we ensure
that the bytearray is resizable without relying on implementation details. So
while this doesn’t fix any observable bug, it increases compatiblity with other
and future Python implementations.

#ifndef HG_MPATCH_H
#define HG_MPATCH_H

#define MPATCH_ERR_NO_MEM -3
#define MPATCH_ERR_CANNOT_BE_DECODED -2
#define MPATCH_ERR_INVALID_PATCH -1

struct mpatch_frag {
	int start, end, len;
	const char *data;
};

struct mpatch_flist {
	struct mpatch_frag *base, *head, *tail;
};

int mpatch_decode(const char *bin, ssize_t len, struct mpatch_flist **res);
ssize_t mpatch_calcsize(ssize_t len, struct mpatch_flist *l);
void mpatch_lfree(struct mpatch_flist *a);
int mpatch_apply(char *buf, const char *orig, ssize_t len,
                 struct mpatch_flist *l);
struct mpatch_flist *
mpatch_fold(void *bins, struct mpatch_flist *(*get_next_item)(void *, ssize_t),
            ssize_t start, ssize_t end);

#endif