thodg/libgit2/src/diff_xdiff.c

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• Hash : 114f5a6c
  Author :
  Date : 2013-06-10T10:10:39
  

  Reorganize diff and add basic diff driver This is a significant reorganization of the diff code to break it into a set of more clearly distinct files and to document the new organization. Hopefully this will make the diff code easier to understand and to extend. This adds a new `git_diff_driver` object that looks of diff driver information from the attributes and the config so that things like function content in diff headers can be provided. The full driver spec is not implemented in the commit - this is focused on the reorganization of the code and putting the driver hooks in place. This also removes a few #includes from src/repository.h that were overbroad, but as a result required extra #includes in a variety of places since including src/repository.h no longer results in pulling in the whole world.

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• src/diff_xdiff.c

• /*
   * Copyright (C) the libgit2 contributors. All rights reserved.
   *
   * This file is part of libgit2, distributed under the GNU GPL v2 with
   * a Linking Exception. For full terms see the included COPYING file.
   */
  #include "common.h"
  #include "diff.h"
  #include "diff_driver.h"
  #include "diff_patch.h"
  #include "diff_xdiff.h"
  
  static int git_xdiff_scan_int(const char **str, int *value)
  {
  	const char *scan = *str;
  	int v = 0, digits = 0;
  	/* find next digit */
  	for (scan = *str; *scan && !git__isdigit(*scan); scan++);
  	/* parse next number */
  	for (; git__isdigit(*scan); scan++, digits++)
  		v = (v * 10) + (*scan - '0');
  	*str = scan;
  	*value = v;
  	return (digits > 0) ? 0 : -1;
  }
  
  static int git_xdiff_parse_hunk(git_diff_range *range, const char *header)
  {
  	/* expect something of the form "@@ -%d[,%d] +%d[,%d] @@" */
  	if (*header != '@')
  		return -1;
  	if (git_xdiff_scan_int(&header, &range->old_start) < 0)
  		return -1;
  	if (*header == ',') {
  		if (git_xdiff_scan_int(&header, &range->old_lines) < 0)
  			return -1;
  	} else
  		range->old_lines = 1;
  	if (git_xdiff_scan_int(&header, &range->new_start) < 0)
  		return -1;
  	if (*header == ',') {
  		if (git_xdiff_scan_int(&header, &range->new_lines) < 0)
  			return -1;
  	} else
  		range->new_lines = 1;
  	if (range->old_start < 0 || range->new_start < 0)
  		return -1;
  
  	return 0;
  }
  
  typedef struct {
  	git_xdiff_output *xo;
  	git_diff_patch *patch;
  	git_diff_range range;
  } git_xdiff_info;
  
  static int git_xdiff_cb(void *priv, mmbuffer_t *bufs, int len)
  {
  	git_xdiff_info *info = priv;
  	git_diff_patch *patch = info->patch;
  	git_diff_output *output = &info->xo->output;
  
  	if (len == 1) {
  		output->error = git_xdiff_parse_hunk(&info->range, bufs[0].ptr);
  		if (output->error < 0)
  			return output->error;
  
  		if (output->hunk_cb != NULL &&
  			output->hunk_cb(patch->delta, &info->range,
  				bufs[0].ptr, bufs[0].size, output->payload))
  			output->error = GIT_EUSER;
  	}
  
  	if (len == 2 || len == 3) {
  		/* expect " "/"-"/"+", then data */
  		char origin =
  			(*bufs[0].ptr == '+') ? GIT_DIFF_LINE_ADDITION :
  			(*bufs[0].ptr == '-') ? GIT_DIFF_LINE_DELETION :
  			GIT_DIFF_LINE_CONTEXT;
  
  		if (output->data_cb != NULL &&
  			output->data_cb(patch->delta, &info->range,
  				origin, bufs[1].ptr, bufs[1].size, output->payload))
  			output->error = GIT_EUSER;
  	}
  
  	if (len == 3 && !output->error) {
  		/* If we have a '+' and a third buf, then we have added a line
  		 * without a newline and the old code had one, so DEL_EOFNL.
  		 * If we have a '-' and a third buf, then we have removed a line
  		 * with out a newline but added a blank line, so ADD_EOFNL.
  		 */
  		char origin =
  			(*bufs[0].ptr == '+') ? GIT_DIFF_LINE_DEL_EOFNL :
  			(*bufs[0].ptr == '-') ? GIT_DIFF_LINE_ADD_EOFNL :
  			GIT_DIFF_LINE_CONTEXT_EOFNL;
  
  		if (output->data_cb != NULL &&
  			output->data_cb(patch->delta, &info->range,
  				origin, bufs[2].ptr, bufs[2].size, output->payload))
  			output->error = GIT_EUSER;
  	}
  
  	return output->error;
  }
  
  static int git_xdiff(git_diff_output *output, git_diff_patch *patch)
  {
  	git_xdiff_output *xo = (git_xdiff_output *)output;
  	git_xdiff_info info;
  	mmfile_t old_xdiff_data, new_xdiff_data;
  
  	memset(&info, 0, sizeof(info));
  	info.patch = patch;
  	info.xo    = xo;
  
  	xo->callback.priv = &info;
  
  	xo->config.find_func_priv = patch->ofile.driver;
  	xo->config.find_func = patch->ofile.driver ?
  		git_diff_driver_find_content_fn(patch->ofile.driver) : NULL;
  
  	if (xo->config.find_func != NULL)
  		xo->config.flags |= XDL_EMIT_FUNCNAMES;
  	else
  		xo->config.flags &= ~XDL_EMIT_FUNCNAMES;
  
  
  	old_xdiff_data.ptr  = patch->ofile.map.data;
  	old_xdiff_data.size = patch->ofile.map.len;
  	new_xdiff_data.ptr  = patch->nfile.map.data;
  	new_xdiff_data.size = patch->nfile.map.len;
  
  	xdl_diff(&old_xdiff_data, &new_xdiff_data,
  		&xo->params, &xo->config, &xo->callback);
  
  	return xo->output.error;
  }
  
  void git_xdiff_init(git_xdiff_output *xo, const git_diff_options *opts)
  {
  	uint32_t flags = opts ? opts->flags : GIT_DIFF_NORMAL;
  
  	xo->output.diff_cb = git_xdiff;
  
  	memset(&xo->config, 0, sizeof(xo->config));
  	xo->config.ctxlen = opts ? opts->context_lines : 3;
  	xo->config.interhunkctxlen = opts ? opts->interhunk_lines : 0;
  
  	memset(&xo->params, 0, sizeof(xo->params));
  	if (flags & GIT_DIFF_IGNORE_WHITESPACE)
  		xo->params.flags |= XDF_WHITESPACE_FLAGS;
  	if (flags & GIT_DIFF_IGNORE_WHITESPACE_CHANGE)
  		xo->params.flags |= XDF_IGNORE_WHITESPACE_CHANGE;
  	if (flags & GIT_DIFF_IGNORE_WHITESPACE_EOL)
  		xo->params.flags |= XDF_IGNORE_WHITESPACE_AT_EOL;
  
  	memset(&xo->callback, 0, sizeof(xo->callback));
  	xo->callback.outf = git_xdiff_cb;
  }
  

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