'--color-words' algorithm can be described as:
1. collect a the minus/plus lines of a diff hunk, divided into
minus-lines and plus-lines;
2. break both minus-lines and plus-lines into words and
place them into two mmfile_t with one word for each line;
3. use xdiff to run diff on the two mmfile_t to get the words level diff;
And for the common parts of the both file, we output the plus side text.
diff_words->current_plus is used to trace the current position of the plus file
which printed. diff_words->last_minus is used to trace the last minus word
printed.
For '--graph' to work with '--color-words', we need to output the graph prefix
on each line of color words output. Generally, there are two conditions on
which we should output the prefix.
1. diff_words->last_minus == 0 &&
diff_words->current_plus == diff_words->plus.text.ptr
that is: the plus text must start as a new line, and if there is no minus
word printed, a graph prefix must be printed.
2. diff_words->current_plus > diff_words->plus.text.ptr &&
*(diff_words->current_plus - 1) == '\n'
that is: a graph prefix must be printed following a '\n'
Signed-off-by: Bo Yang <struggleyb.nku@xxxxxxxxx>
---
diff.c | 121 +++++++++++++++++++++++++++++++++++++++++++++++++++++++---------
1 files changed, 104 insertions(+), 17 deletions(-)
diff --git a/diff.c b/diff.c
index 8b738f0..030fceb 100644
--- a/diff.c
+++ b/diff.c
@@ -624,7 +624,8 @@ struct diff_words_style diff_words_styles[] = {
struct diff_words_data {
struct diff_words_buffer minus, plus;
const char *current_plus;
- FILE *file;
+ int last_minus;
+ struct diff_options *opt;
regex_t *word_regex;
enum diff_words_type type;
struct diff_words_style *style;
@@ -633,10 +634,15 @@ struct diff_words_data {
static int fn_out_diff_words_write_helper(FILE *fp,
struct diff_words_style_elem *st_el,
const char *newline,
- size_t count, const char *buf)
+ size_t count, const char *buf,
+ const char *line_prefix)
{
+ int print = 0;
+
while (count) {
char *p = memchr(buf, '\n', count);
+ if (print)
+ fputs(line_prefix, fp);
if (p != buf) {
if (st_el->color && fputs(st_el->color, fp) < 0)
return -1;
@@ -654,21 +660,74 @@ static int fn_out_diff_words_write_helper(FILE *fp,
return -1;
count -= p + 1 - buf;
buf = p + 1;
+ print = 1;
}
return 0;
}
+/*
+ * '--color-words' algorithm can be described as:
+ *
+ * 1. collect a the minus/plus lines of a diff hunk, divided into
+ * minus-lines and plus-lines;
+ *
+ * 2. break both minus-lines and plus-lines into words and
+ * place them into two mmfile_t with one word for each line;
+ *
+ * 3. use xdiff to run diff on the two mmfile_t to get the words level diff;
+ *
+ * And for the common parts of the both file, we output the plus side text.
+ * diff_words->current_plus is used to trace the current position of the plus file
+ * which printed. diff_words->last_minus is used to trace the last minus word
+ * printed.
+ *
+ * For '--graph' to work with '--color-words', we need to output the graph prefix
+ * on each line of color words output. Generally, there are two conditions on
+ * which we should output the prefix.
+ *
+ * 1. diff_words->last_minus == 0 &&
+ * diff_words->current_plus == diff_words->plus.text.ptr
+ *
+ * that is: the plus text must start as a new line, and if there is no minus
+ * word printed, a graph prefix must be printed.
+ *
+ * 2. diff_words->current_plus > diff_words->plus.text.ptr &&
+ * *(diff_words->current_plus - 1) == '\n'
+ *
+ * that is: a graph prefix must be printed following a '\n'
+ */
+static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
+{
+ if ((diff_words->last_minus == 0 &&
+ diff_words->current_plus == diff_words->plus.text.ptr) ||
+ (diff_words->current_plus > diff_words->plus.text.ptr &&
+ *(diff_words->current_plus - 1) == '\n')) {
+ return 1;
+ } else {
+ return 0;
+ }
+}
+
static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
{
struct diff_words_data *diff_words = priv;
struct diff_words_style *style = diff_words->style;
int minus_first, minus_len, plus_first, plus_len;
const char *minus_begin, *minus_end, *plus_begin, *plus_end;
+ struct diff_options *opt = diff_words->opt;
+ struct strbuf *msgbuf;
+ char *line_prefix = "";
if (line[0] != '@' || parse_hunk_header(line, len,
&minus_first, &minus_len, &plus_first, &plus_len))
return;
+ assert(opt);
+ if (opt->output_prefix) {
+ msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
+ line_prefix = msgbuf->buf;
+ }
+
/* POSIX requires that first be decremented by one if len == 0... */
if (minus_len) {
minus_begin = diff_words->minus.orig[minus_first].begin;
@@ -684,21 +743,32 @@ static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
} else
plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
- if (diff_words->current_plus != plus_begin)
- fn_out_diff_words_write_helper(diff_words->file,
+ if (color_words_output_graph_prefix(diff_words)) {
+ fputs(line_prefix, diff_words->opt->file);
+ }
+ if (diff_words->current_plus != plus_begin) {
+ fn_out_diff_words_write_helper(diff_words->opt->file,
&style->ctx, style->newline,
plus_begin - diff_words->current_plus,
- diff_words->current_plus);
- if (minus_begin != minus_end)
- fn_out_diff_words_write_helper(diff_words->file,
+ diff_words->current_plus, line_prefix);
+ if (*(plus_begin - 1) == '\n')
+ fputs(line_prefix, diff_words->opt->file);
+ }
+ if (minus_begin != minus_end) {
+ fn_out_diff_words_write_helper(diff_words->opt->file,
&style->old, style->newline,
- minus_end - minus_begin, minus_begin);
- if (plus_begin != plus_end)
- fn_out_diff_words_write_helper(diff_words->file,
+ minus_end - minus_begin, minus_begin,
+ line_prefix);
+ }
+ if (plus_begin != plus_end) {
+ fn_out_diff_words_write_helper(diff_words->opt->file,
&style->new, style->newline,
- plus_end - plus_begin, plus_begin);
+ plus_end - plus_begin, plus_begin,
+ line_prefix);
+ }
diff_words->current_plus = plus_end;
+ diff_words->last_minus = minus_first;
}
/* This function starts looking at *begin, and returns 0 iff a word was found. */
@@ -779,16 +849,29 @@ static void diff_words_show(struct diff_words_data *diff_words)
mmfile_t minus, plus;
struct diff_words_style *style = diff_words->style;
+ struct diff_options *opt = diff_words->opt;
+ struct strbuf *msgbuf;
+ char *line_prefix = "";
+
+ assert(opt);
+ if (opt->output_prefix) {
+ msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
+ line_prefix = msgbuf->buf;
+ }
+
/* special case: only removal */
if (!diff_words->plus.text.size) {
- fn_out_diff_words_write_helper(diff_words->file,
+ fputs(line_prefix, diff_words->opt->file);
+ fn_out_diff_words_write_helper(diff_words->opt->file,
&style->old, style->newline,
- diff_words->minus.text.size, diff_words->minus.text.ptr);
+ diff_words->minus.text.size,
+ diff_words->minus.text.ptr, line_prefix);
diff_words->minus.text.size = 0;
return;
}
diff_words->current_plus = diff_words->plus.text.ptr;
+ diff_words->last_minus = 0;
memset(&xpp, 0, sizeof(xpp));
memset(&xecfg, 0, sizeof(xecfg));
@@ -802,11 +885,15 @@ static void diff_words_show(struct diff_words_data *diff_words)
free(minus.ptr);
free(plus.ptr);
if (diff_words->current_plus != diff_words->plus.text.ptr +
- diff_words->plus.text.size)
- fn_out_diff_words_write_helper(diff_words->file,
+ diff_words->plus.text.size) {
+ if (color_words_output_graph_prefix(diff_words))
+ fputs(line_prefix, diff_words->opt->file);
+ fn_out_diff_words_write_helper(diff_words->opt->file,
&style->ctx, style->newline,
diff_words->plus.text.ptr + diff_words->plus.text.size
- - diff_words->current_plus, diff_words->current_plus);
+ - diff_words->current_plus, diff_words->current_plus,
+ line_prefix);
+ }
diff_words->minus.text.size = diff_words->plus.text.size = 0;
}
@@ -1904,8 +1991,8 @@ static void builtin_diff(const char *name_a,
ecbdata.diff_words =
xcalloc(1, sizeof(struct diff_words_data));
- ecbdata.diff_words->file = o->file;
ecbdata.diff_words->type = o->word_diff;
+ ecbdata.diff_words->opt = o;
if (!o->word_regex)
o->word_regex = userdiff_word_regex(one);
if (!o->word_regex)
--
1.7.0.2.273.gc2413.dirty
--
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