thodg/got/lib/blame.c

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• Hash : 06ca4d09
  Author :
  Date : 2018-11-19T10:14:24
  

  stop history traversal once blame has annotated all lines

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• lib/blame.c

• /*
   * Copyright (c) 2018 Stefan Sperling <stsp@openbsd.org>
   *
   * Permission to use, copy, modify, and distribute this software for any
   * purpose with or without fee is hereby granted, provided that the above
   * copyright notice and this permission notice appear in all copies.
   *
   * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
   * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
   * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
   * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
   * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
   * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
   */
  
  #include <sys/queue.h>
  #include <sys/stat.h>
  
  #include <sha1.h>
  #include <string.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <time.h>
  #include <util.h>
  #include <zlib.h>
  
  #include "got_error.h"
  #include "got_object.h"
  #include "got_blame.h"
  #include "got_opentemp.h"
  
  #include "got_lib_inflate.h"
  #include "got_lib_delta.h"
  #include "got_lib_object.h"
  #include "got_lib_diff.h"
  #include "got_lib_diffoffset.h"
  #include "got_commit_graph.h"
  
  struct got_blame_line {
  	int annotated;
  	struct got_object_id id;
  };
  
  struct got_blame_diff_offsets {
  	struct got_diffoffset_chunks *chunks;
  	struct got_object_id *commit_id;
  	SLIST_ENTRY(got_blame_diff_offsets) entry;
  };
  
  SLIST_HEAD(got_blame_diff_offsets_list, got_blame_diff_offsets);
  
  struct got_blame {
  	FILE *f;
  	int nlines;
  	int nannotated;
  	struct got_blame_line *lines; /* one per line */
  	int ncommits;
  	struct got_blame_diff_offsets_list diff_offsets_list;
  };
  
  static void
  free_diff_offsets(struct got_blame_diff_offsets *diff_offsets)
  {
  	if (diff_offsets->chunks)
  		got_diffoffset_free(diff_offsets->chunks);
  	free(diff_offsets->commit_id);
  	free(diff_offsets);
  }
  
  static const struct got_error *
  alloc_diff_offsets(struct got_blame_diff_offsets **diff_offsets,
      struct got_object_id *commit_id)
  {
  	const struct got_error *err = NULL;
  
  	*diff_offsets = calloc(1, sizeof(**diff_offsets));
  	if (*diff_offsets == NULL)
  		return got_error_from_errno();
  
  	(*diff_offsets)->commit_id = got_object_id_dup(commit_id);
  	if ((*diff_offsets)->commit_id == NULL) {
  		err = got_error_from_errno();
  		free_diff_offsets(*diff_offsets);
  		*diff_offsets = NULL;
  		return err;
  	}
  
  	err = got_diffoffset_alloc(&(*diff_offsets)->chunks);
  	if (err) {
  		free_diff_offsets(*diff_offsets);
  		return err;
  	}
  
  	return NULL;
  }
  
  static const struct got_error *
  annotate_line(struct got_blame *blame, int lineno, struct got_object_id *id,
      const struct got_error *(*cb)(void *, int, int, struct got_object_id *),
      void *arg)
  {
  	const struct got_error *err = NULL;
  	struct got_blame_line *line;
  
  	if (lineno < 1 || lineno > blame->nlines)
  		return NULL;
  	
  	line = &blame->lines[lineno - 1];
  	if (line->annotated)
  		return NULL;
  
  	memcpy(&line->id, id, sizeof(line->id));
  	line->annotated = 1;
  	blame->nannotated++;
  	if (cb)
  		err = cb(arg, blame->nlines, lineno, id);
  	return err;
  }
  
  static int
  get_blamed_line(struct got_blame_diff_offsets_list *diff_offsets_list,
      int lineno)
  {
  	struct got_blame_diff_offsets *diff_offsets;
  
  	SLIST_FOREACH(diff_offsets, diff_offsets_list, entry)
  		lineno = got_diffoffset_get(diff_offsets->chunks, lineno);
  
  	return lineno;
  }
  
  static const struct got_error *
  blame_changes(struct got_blame *blame, struct got_diff_changes *changes,
      struct got_object_id *commit_id,
      const struct got_error *(*cb)(void *, int, int, struct got_object_id *),
      void *arg)
  {
  	const struct got_error *err = NULL;
  	struct got_diff_change *change;
  	struct got_blame_diff_offsets *diff_offsets;
  
  	SIMPLEQ_FOREACH(change, &changes->entries, entry) {
  		int c = change->cv.c;
  		int d = change->cv.d;
  		int new_lineno = c;
  		int new_length = (c < d ? d - c + 1 : (c == d ? 1 : 0));
  		int ln;
  
  		for (ln = new_lineno; ln < new_lineno + new_length; ln++) {
  			err = annotate_line(blame,
  			    get_blamed_line(&blame->diff_offsets_list, ln),
  			    commit_id, cb, arg);
  			if (err)
  				return err;
  			if (blame->nlines == blame->nannotated)
  				return NULL;
  		}
  	}
  
  	err = alloc_diff_offsets(&diff_offsets, commit_id);
  	if (err)
  		return err;
  	SIMPLEQ_FOREACH(change, &changes->entries, entry) {
  		int a = change->cv.a;
  		int b = change->cv.b;
  		int c = change->cv.c;
  		int d = change->cv.d;
  		int old_lineno = a;
  		int old_length = (a < b ? b - a + 1 : (a == b ? 1 : 0));
  		int new_lineno = c;
  		int new_length = (c < d ? d - c + 1 : (c == d ? 1 : 0));
  
  		err = got_diffoffset_add(diff_offsets->chunks,
  		    old_lineno, old_length, new_lineno, new_length);
  		if (err) {
  			free_diff_offsets(diff_offsets);
  			return err;
  		}
  	}
  	SLIST_INSERT_HEAD(&blame->diff_offsets_list, diff_offsets, entry);
  
  	return NULL;
  }
  
  static const struct got_error *
  blame_commit(struct got_blame *blame, struct got_object_id *id,
      struct got_object_id *pid, const char *path, struct got_repository *repo,
      const struct got_error *(*cb)(void *, int, int, struct got_object_id *),
      void *arg)
  {
  	const struct got_error *err = NULL;
  	struct got_object *obj = NULL, *pobj = NULL;
  	struct got_object_id *obj_id = NULL, *pobj_id = NULL;
  	struct got_blob_object *blob = NULL, *pblob = NULL;
  	struct got_diff_changes *changes = NULL;
  
  	err = got_object_id_by_path(&obj_id, repo, id, path);
  	if (err)
  		goto done;
  
  	err = got_object_open(&obj, repo, obj_id);
  	if (err)
  		goto done;
  
  	if (got_object_get_type(obj) != GOT_OBJ_TYPE_BLOB) {
  		err = got_error(GOT_ERR_OBJ_TYPE);
  		goto done;
  	}
  
  	err = got_object_id_by_path(&pobj_id, repo, pid, path);
  	if (err) {
  		if (err->code == GOT_ERR_NO_TREE_ENTRY) {
  			/* Blob's history began in previous commit. */
  			err = got_error(GOT_ERR_ITER_COMPLETED);
  		}
  		goto done;
  	}
  
  	/* If IDs match then don't bother with diffing. */
  	if (got_object_id_cmp(obj_id, pobj_id) == 0) {
  		if (cb)
  			err = cb(arg, blame->nlines, -1, id);
  		goto done;
  	}
  
  	err = got_object_open(&pobj, repo, pobj_id);
  	if (err)
  		goto done;
  
  	if (got_object_get_type(pobj) != GOT_OBJ_TYPE_BLOB) {
  		/*
  		 * Encountered a non-blob at the path (probably a tree).
  		 * Blob's history began in previous commit.
  		 */
  		err = got_error(GOT_ERR_ITER_COMPLETED);
  		goto done;
  	}
  
  	err = got_object_blob_open(&blob, repo, obj, 8192);
  	if (err)
  		goto done;
  
  	err = got_object_blob_open(&pblob, repo, pobj, 8192);
  	if (err)
  		goto done;
  
  	err = got_diff_blob_lines_changed(&changes, pblob, blob);
  	if (err)
  		goto done;
  
  	if (changes) {
  		err = blame_changes(blame, changes, id, cb, arg);
  		got_diff_free_changes(changes);
  	} else if (cb)
  		err = cb(arg, blame->nlines, -1, id);
  done:
  	free(obj_id);
  	free(pobj_id);
  	if (obj)
  		got_object_close(obj);
  	if (pobj)
  		got_object_close(pobj);
  	if (blob)
  		got_object_blob_close(blob);
  	if (pblob)
  		got_object_blob_close(pblob);
  	return err;
  }
  
  static void
  blame_close(struct got_blame *blame)
  {
  	struct got_blame_diff_offsets *diff_offsets;
  
  	if (blame->f)
  		fclose(blame->f);
  	free(blame->lines);
  	while (!SLIST_EMPTY(&blame->diff_offsets_list)) {
  		diff_offsets = SLIST_FIRST(&blame->diff_offsets_list);
  		SLIST_REMOVE_HEAD(&blame->diff_offsets_list, entry);
  		free_diff_offsets(diff_offsets);
  	}
  	free(blame);
  }
  
  static const struct got_error *
  blame_open(struct got_blame **blamep, const char *path,
      struct got_object_id *start_commit_id, struct got_repository *repo,
      const struct got_error *(*cb)(void *, int, int, struct got_object_id *),
      void *arg)
  {
  	const struct got_error *err = NULL;
  	struct got_object *obj = NULL;
  	struct got_object_id *obj_id = NULL;
  	struct got_blob_object *blob = NULL;
  	struct got_blame *blame = NULL;
  	struct got_object_id *id = NULL;
  	int lineno;
  	struct got_commit_graph *graph = NULL;
  
  	*blamep = NULL;
  
  	err = got_object_id_by_path(&obj_id, repo, start_commit_id, path);
  	if (err)
  		return err;
  
  	err = got_object_open(&obj, repo, obj_id);
  	if (err)
  		goto done;
  
  	if (got_object_get_type(obj) != GOT_OBJ_TYPE_BLOB) {
  		err = got_error(GOT_ERR_OBJ_TYPE);
  		goto done;
  	}
  
  	err = got_object_blob_open(&blob, repo, obj, 8192);
  	if (err)
  		goto done;
  
  	blame = calloc(1, sizeof(*blame));
  	if (blame == NULL)
  		return got_error_from_errno();
  
  	blame->f = got_opentemp();
  	if (blame->f == NULL) {
  		err = got_error_from_errno();
  		goto done;
  	}
  	err = got_object_blob_dump_to_file(NULL, &blame->nlines, blame->f,
  	    blob);
  	if (err)
  		goto done;
  
  	blame->lines = calloc(blame->nlines, sizeof(*blame->lines));
  	if (blame->lines == NULL) {
  		err = got_error_from_errno();
  		goto done;
  	}
  
  	err = got_commit_graph_open(&graph, start_commit_id, path, 0, repo);
  	if (err)
  		return err;
  	err = got_commit_graph_iter_start(graph, start_commit_id, repo);
  	if (err)
  		goto done;
  
  	id = NULL;
  	while (1) {
  		struct got_object_id *next_id;
  
  		err = got_commit_graph_iter_next(&next_id, graph);
  		if (err) {
  			if (err->code == GOT_ERR_ITER_COMPLETED) {
  				err = NULL;
  				break;
  			}
  			if (err->code != GOT_ERR_ITER_NEED_MORE)
  				break;
  			err = got_commit_graph_fetch_commits(graph, 1, repo);
  			if (err)
  				break;
  			else
  				continue;
  		}
  		if (next_id == NULL)
  			break;
  		if (id) {
  			err = blame_commit(blame, id, next_id, path, repo,
  			    cb, arg);
  			if (err) {
  				if (err->code == GOT_ERR_ITER_COMPLETED)
  					err = NULL;
  				break;
  			}
  			if (blame->nannotated == blame->nlines)
  				break;
  		}
  		id = next_id;
  	}
  
  	if (id && blame->nannotated < blame->nlines) {
  		/* Annotate remaining non-annotated lines with last commit. */
  		for (lineno = 1; lineno <= blame->nlines; lineno++) {
  			err = annotate_line(blame, lineno, id, cb, arg);
  			if (err)
  				goto done;
  		}
  	}
  
  done:
  	if (graph)
  		got_commit_graph_close(graph);
  	free(obj_id);
  	if (obj)
  		got_object_close(obj);
  	if (blob)
  		got_object_blob_close(blob);
  	if (err) {
  		if (blame)
  			blame_close(blame);
  	} else
  		*blamep = blame;
  
  	return err;
  }
  
  static const struct got_error *
  blame_line(struct got_object_id **id, struct got_blame *blame, int lineno)
  {
  	if (lineno < 1 || lineno > blame->nlines)
  		return got_error(GOT_ERR_RANGE);
  	*id = &blame->lines[lineno - 1].id;
  	return NULL;
  }
  
  static char *
  parse_next_line(FILE *f, size_t *len)
  {
  	char *line;
  	size_t linelen;
  	size_t lineno;
  	const char delim[3] = { '\0', '\0', '\0'};
  
  	line = fparseln(f, &linelen, &lineno, delim, 0);
  	if (len)
  		*len = linelen;
  	return line;
  }
  
  const struct got_error *
  got_blame(const char *path, struct got_object_id *start_commit_id,
      struct got_repository *repo, FILE *outfile)
  {
  	const struct got_error *err = NULL;
  	struct got_blame *blame;
  	int lineno;
  	char *abspath;
  
  	if (asprintf(&abspath, "%s%s", path[0] == '/' ? "" : "/", path) == -1)
  		return got_error_from_errno();
  
  	err = blame_open(&blame, abspath, start_commit_id, repo, NULL, NULL);
  	if (err) {
  		free(abspath);
  		return err;
  	}
  
  	for (lineno = 1; lineno <= blame->nlines; lineno++) {
  		struct got_object_id *id;
  		char *line, *id_str;
  		
  		line = parse_next_line(blame->f, NULL);
  		if (line == NULL)
  			break;
  
  		err = blame_line(&id, blame, lineno);
  		if (err) {
  			free(line);
  			break;
  		}
  
  		err = got_object_id_str(&id_str, id);
  		/* Do not free id; It points into blame->lines. */
  		if (err) {
  			free(line);
  			break;
  		}
  
  		fprintf(outfile, "%.8s %s\n", id_str, line);
  		free(line);
  		free(id_str);
  	}
  
  	blame_close(blame);
  	free(abspath);
  	return err;
  }
  
  const struct got_error *
  got_blame_incremental(const char *path, struct got_object_id *commit_id,
      struct got_repository *repo,
      const struct got_error *(*cb)(void *, int, int, struct got_object_id *),
      void *arg)
  {
  	const struct got_error *err = NULL;
  	struct got_blame *blame;
  	char *abspath;
  
  	if (asprintf(&abspath, "%s%s", path[0] == '/' ? "" : "/", path) == -1)
  		return got_error_from_errno();
  
  	err = blame_open(&blame, abspath, commit_id, repo, cb, arg);
  	free(abspath);
  	if (blame)
  		blame_close(blame);
  	return err;
  }
  

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