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-rw-r--r--ui-ssdiff.c369
1 files changed, 369 insertions, 0 deletions
diff --git a/ui-ssdiff.c b/ui-ssdiff.c
new file mode 100644
index 0000000..408e620
--- /dev/null
+++ b/ui-ssdiff.c
@@ -0,0 +1,369 @@
+#include "cgit.h"
+#include "html.h"
+#include "ui-shared.h"
+
+extern int use_ssdiff;
+
+static int current_old_line, current_new_line;
+
+struct deferred_lines {
+ int line_no;
+ char *line;
+ struct deferred_lines *next;
+};
+
+static struct deferred_lines *deferred_old, *deferred_old_last;
+static struct deferred_lines *deferred_new, *deferred_new_last;
+
+static char *longest_common_subsequence(char *A, char *B)
+{
+ int i, j, ri;
+ int m = strlen(A);
+ int n = strlen(B);
+ int L[m + 1][n + 1];
+ int tmp1, tmp2;
+ int lcs_length;
+ char *result;
+
+ for (i = m; i >= 0; i--) {
+ for (j = n; j >= 0; j--) {
+ if (A[i] == '\0' || B[j] == '\0') {
+ L[i][j] = 0;
+ } else if (A[i] == B[j]) {
+ L[i][j] = 1 + L[i + 1][j + 1];
+ } else {
+ tmp1 = L[i + 1][j];
+ tmp2 = L[i][j + 1];
+ L[i][j] = (tmp1 > tmp2 ? tmp1 : tmp2);
+ }
+ }
+ }
+
+ lcs_length = L[0][0];
+ result = xmalloc(lcs_length + 2);
+ memset(result, 0, sizeof(*result) * (lcs_length + 2));
+
+ ri = 0;
+ i = 0;
+ j = 0;
+ while (i < m && j < n) {
+ if (A[i] == B[j]) {
+ result[ri] = A[i];
+ ri += 1;
+ i += 1;
+ j += 1;
+ } else if (L[i + 1][j] >= L[i][j + 1]) {
+ i += 1;
+ } else {
+ j += 1;
+ }
+ }
+ return result;
+}
+
+static int line_from_hunk(char *line, char type)
+{
+ char *buf1, *buf2;
+ int len;
+
+ buf1 = strchr(line, type);
+ if (buf1 == NULL)
+ return 0;
+ buf1 += 1;
+ buf2 = strchr(buf1, ',');
+ if (buf2 == NULL)
+ return 0;
+ len = buf2 - buf1;
+ buf2 = xmalloc(len + 1);
+ strncpy(buf2, buf1, len);
+ buf2[len] = '\0';
+ int res = atoi(buf2);
+ free(buf2);
+ return res;
+}
+
+static char *replace_tabs(char *line)
+{
+ char *prev_buf = line;
+ char *cur_buf;
+ int linelen = strlen(line);
+ int n_tabs = 0;
+ int i;
+ char *result;
+ char *spaces = " ";
+
+ if (linelen == 0) {
+ result = xmalloc(1);
+ result[0] = '\0';
+ return result;
+ }
+
+ for (i = 0; i < linelen; i++)
+ if (line[i] == '\t')
+ n_tabs += 1;
+ result = xmalloc(linelen + n_tabs * 8 + 1);
+ result[0] = '\0';
+
+ while (1) {
+ cur_buf = strchr(prev_buf, '\t');
+ if (!cur_buf) {
+ strcat(result, prev_buf);
+ break;
+ } else {
+ strcat(result, " ");
+ strncat(result, spaces, 8 - (strlen(result) % 8));
+ strncat(result, prev_buf, cur_buf - prev_buf);
+ }
+ prev_buf = cur_buf + 1;
+ }
+ return result;
+}
+
+static int calc_deferred_lines(struct deferred_lines *start)
+{
+ struct deferred_lines *item = start;
+ int result = 0;
+ while (item) {
+ result += 1;
+ item = item->next;
+ }
+ return result;
+}
+
+static void deferred_old_add(char *line, int line_no)
+{
+ struct deferred_lines *item = xmalloc(sizeof(struct deferred_lines));
+ item->line = xstrdup(line);
+ item->line_no = line_no;
+ item->next = NULL;
+ if (deferred_old) {
+ deferred_old_last->next = item;
+ deferred_old_last = item;
+ } else {
+ deferred_old = deferred_old_last = item;
+ }
+}
+
+static void deferred_new_add(char *line, int line_no)
+{
+ struct deferred_lines *item = xmalloc(sizeof(struct deferred_lines));
+ item->line = xstrdup(line);
+ item->line_no = line_no;
+ item->next = NULL;
+ if (deferred_new) {
+ deferred_new_last->next = item;
+ deferred_new_last = item;
+ } else {
+ deferred_new = deferred_new_last = item;
+ }
+}
+
+static void print_part_with_lcs(char *class, char *line, char *lcs)
+{
+ int line_len = strlen(line);
+ int i, j;
+ char c[2] = " ";
+ int same = 1;
+
+ j = 0;
+ for (i = 0; i < line_len; i++) {
+ c[0] = line[i];
+ if (same) {
+ if (line[i] == lcs[j])
+ j += 1;
+ else {
+ same = 0;
+ htmlf("<span class='%s'>", class);
+ }
+ } else if (line[i] == lcs[j]) {
+ same = 1;
+ htmlf("</span>");
+ j += 1;
+ }
+ html_txt(c);
+ }
+}
+
+static void print_ssdiff_line(char *class,
+ int old_line_no,
+ char *old_line,
+ int new_line_no,
+ char *new_line, int individual_chars)
+{
+ char *lcs = NULL;
+ if (old_line)
+ old_line = replace_tabs(old_line + 1);
+ if (new_line)
+ new_line = replace_tabs(new_line + 1);
+ if (individual_chars && old_line && new_line)
+ lcs = longest_common_subsequence(old_line, new_line);
+ html("<tr>");
+ if (old_line_no > 0)
+ htmlf("<td class='lineno'>%d</td><td class='%s'>",
+ old_line_no, class);
+ else if (old_line)
+ htmlf("<td class='lineno'></td><td class='%s'>", class);
+ else
+ htmlf("<td class='lineno'></td><td class='%s_dark'>", class);
+ if (old_line) {
+ if (lcs)
+ print_part_with_lcs("del", old_line, lcs);
+ else
+ html_txt(old_line);
+ }
+
+ html("</td>");
+ if (new_line_no > 0)
+ htmlf("<td class='lineno'>%d</td><td class='%s'>",
+ new_line_no, class);
+ else if (new_line)
+ htmlf("<td class='lineno'></td><td class='%s'>", class);
+ else
+ htmlf("<td class='lineno'></td><td class='%s_dark'>", class);
+ if (new_line) {
+ if (lcs)
+ print_part_with_lcs("add", new_line, lcs);
+ else
+ html_txt(new_line);
+ }
+
+ html("</td></tr>");
+ if (lcs)
+ free(lcs);
+ if (new_line)
+ free(new_line);
+ if (old_line)
+ free(old_line);
+}
+
+static void print_deferred_old_lines()
+{
+ struct deferred_lines *iter_old, *tmp;
+ iter_old = deferred_old;
+ while (iter_old) {
+ print_ssdiff_line("del", iter_old->line_no,
+ iter_old->line, -1, NULL, 0);
+ tmp = iter_old->next;
+ free(iter_old);
+ iter_old = tmp;
+ }
+}
+
+static void print_deferred_new_lines()
+{
+ struct deferred_lines *iter_new, *tmp;
+ iter_new = deferred_new;
+ while (iter_new) {
+ print_ssdiff_line("add", -1, NULL,
+ iter_new->line_no, iter_new->line, 0);
+ tmp = iter_new->next;
+ free(iter_new);
+ iter_new = tmp;
+ }
+}
+
+static void print_deferred_changed_lines()
+{
+ struct deferred_lines *iter_old, *iter_new, *tmp;
+ int n_old_lines = calc_deferred_lines(deferred_old);
+ int n_new_lines = calc_deferred_lines(deferred_new);
+ int individual_chars = (n_old_lines == n_new_lines ? 1 : 0);
+
+ iter_old = deferred_old;
+ iter_new = deferred_new;
+ while (iter_old || iter_new) {
+ if (iter_old && iter_new)
+ print_ssdiff_line("changed", iter_old->line_no,
+ iter_old->line,
+ iter_new->line_no, iter_new->line,
+ individual_chars);
+ else if (iter_old)
+ print_ssdiff_line("changed", iter_old->line_no,
+ iter_old->line, -1, NULL, 0);
+ else if (iter_new)
+ print_ssdiff_line("changed", -1, NULL,
+ iter_new->line_no, iter_new->line, 0);
+ if (iter_old) {
+ tmp = iter_old->next;
+ free(iter_old);
+ iter_old = tmp;
+ }
+
+ if (iter_new) {
+ tmp = iter_new->next;
+ free(iter_new);
+ iter_new = tmp;
+ }
+ }
+}
+
+void cgit_ssdiff_print_deferred_lines()
+{
+ if (!deferred_old && !deferred_new)
+ return;
+ if (deferred_old && !deferred_new)
+ print_deferred_old_lines();
+ else if (!deferred_old && deferred_new)
+ print_deferred_new_lines();
+ else
+ print_deferred_changed_lines();
+ deferred_old = deferred_old_last = NULL;
+ deferred_new = deferred_new_last = NULL;
+}
+
+/*
+ * print a single line returned from xdiff
+ */
+void cgit_ssdiff_line_cb(char *line, int len)
+{
+ char c = line[len - 1];
+ line[len - 1] = '\0';
+ if (line[0] == '@') {
+ current_old_line = line_from_hunk(line, '-');
+ current_new_line = line_from_hunk(line, '+');
+ }
+
+ if (line[0] == ' ') {
+ if (deferred_old || deferred_new)
+ cgit_ssdiff_print_deferred_lines();
+ print_ssdiff_line("ctx", current_old_line, line,
+ current_new_line, line, 0);
+ current_old_line += 1;
+ current_new_line += 1;
+ } else if (line[0] == '+') {
+ deferred_new_add(line, current_new_line);
+ current_new_line += 1;
+ } else if (line[0] == '-') {
+ deferred_old_add(line, current_old_line);
+ current_old_line += 1;
+ } else if (line[0] == '@') {
+ html("<tr><td colspan='4' class='hunk'>");
+ html_txt(line);
+ html("</td></tr>");
+ } else {
+ html("<tr><td colspan='4' class='ctx'>");
+ html_txt(line);
+ html("</td></tr>");
+ }
+ line[len - 1] = c;
+}
+
+void cgit_ssdiff_header_begin()
+{
+ current_old_line = -1;
+ current_new_line = -1;
+ html("<tr><td class='space' colspan='4'><div></div></td></tr>");
+ html("<tr><td class='head' colspan='4'>");
+}
+
+void cgit_ssdiff_header_end()
+{
+ html("</td><tr>");
+}
+
+void cgit_ssdiff_footer()
+{
+ if (deferred_old || deferred_new)
+ cgit_ssdiff_print_deferred_lines();
+ html("<tr><td class='foot' colspan='4'></td></tr>");
+}
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