mercurial/bdiff.h

phabricator: add a small language to query Differential Revisions

Previously, `phabread` can only be used to read a single patch, or a single
stack of patches. In the future, we want to have more complex queries like
filtering with status (open, accepted, closed, etc), or maybe more complex
like filtering by reviewers etc. The command line flag approach won't scale
with that.

Besides, we might want to have other commands to update Differential
Revision status in batch, like accepting a stack using a single command.

Therefore, this patch adds a small language. It has basic set operations:
`&`, `+`, `-` and an ancestor operator to support `--stack`.

Test Plan:
Try querying this Phabricator instance:

  hg phabread 1+2 # 1, 2
  hg phabread D2+D1 # 2, 1
  hg phabread ':118-115+:2-1' # 114, 116, 117, 118, 2
  hg phabread '((:118-(D115+117)))&:117' # 114, 116
  hg phabread ':2&:117' --debug # differential.query is called only once

Make sure the output is expected and prefetch works.

Differential Revision: https://phab.mercurial-scm.org/D125

#ifndef _HG_BDIFF_H_
#define _HG_BDIFF_H_

struct bdiff_line {
	int hash, n, e;
	ssize_t len;
	const char *l;
};

struct bdiff_hunk;
struct bdiff_hunk {
	int a1, a2, b1, b2;
	struct bdiff_hunk *next;
};

int bdiff_splitlines(const char *a, ssize_t len, struct bdiff_line **lr);
int bdiff_diff(struct bdiff_line *a, int an, struct bdiff_line *b, int bn,
	struct bdiff_hunk *base);
void bdiff_freehunks(struct bdiff_hunk *l);

#endif