341 lines
7.3 KiB
C
341 lines
7.3 KiB
C
/* radare - LGPL - Copyright 2009-2010 pancake<nopcode.org> */
|
|
/* Adapted code from:
|
|
|
|
bdiff.c - efficient binary diff extension for Mercurial
|
|
|
|
Copyright 2005, 2006 Matt Mackall <mpm@selenic.com>
|
|
|
|
This software may be used and distributed according to the terms of
|
|
the GNU General Public License, incorporated herein by reference.
|
|
|
|
Based roughly on Python difflib
|
|
*/
|
|
|
|
#include <r_util.h>
|
|
#include <r_diff.h>
|
|
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <limits.h>
|
|
|
|
struct line {
|
|
int h, len, n, e;
|
|
const char *l;
|
|
};
|
|
|
|
struct pos {
|
|
int pos, len;
|
|
};
|
|
|
|
struct hunk {
|
|
int a1, a2, b1, b2;
|
|
};
|
|
|
|
struct hunklist {
|
|
struct hunk *base, *head;
|
|
};
|
|
|
|
static int splitlines(const char *a, int len, struct line **lr)
|
|
{
|
|
int h, i;
|
|
const char *p, *b = a;
|
|
const char * const plast = a + len - 1;
|
|
struct line *l;
|
|
|
|
if (a == NULL) {
|
|
eprintf ("null pointer received\n");
|
|
return 0;
|
|
}
|
|
|
|
/* count the lines */
|
|
i = 1; /* extra line for sentinel */
|
|
for (p = a; p < a + len; p++)
|
|
if (*p == '\n' || p == plast)
|
|
i++;
|
|
|
|
*lr = l = (struct line *)malloc(sizeof(struct line) * i);
|
|
if (!l)
|
|
return -1;
|
|
|
|
/* build the line array and calculate hashes */
|
|
h = 0;
|
|
for (p = a; p < a + len; p++) {
|
|
/* Leonid Yuriev's hash */
|
|
h = (h * 1664525) + *p + 1013904223;
|
|
|
|
if (*p == '\n' || p == plast) {
|
|
l->h = h;
|
|
h = 0;
|
|
l->len = p - b + 1;
|
|
l->l = b;
|
|
l->n = INT_MAX;
|
|
l++;
|
|
b = p + 1;
|
|
}
|
|
}
|
|
|
|
/* set up a sentinel */
|
|
l->h = l->len = 0;
|
|
l->l = a + len;
|
|
return i - 1;
|
|
}
|
|
|
|
static int inline cmp(struct line *a, struct line *b)
|
|
{
|
|
return a->h != b->h || a->len != b->len || memcmp(a->l, b->l, a->len);
|
|
}
|
|
|
|
static int equatelines(struct line *a, int an, struct line *b, int bn)
|
|
{
|
|
int i, j, buckets = 1, t, scale;
|
|
struct pos *h = NULL;
|
|
|
|
/* build a hash table of the next highest power of 2 */
|
|
while (buckets < bn + 1)
|
|
buckets *= 2;
|
|
|
|
/* try to allocate a large hash table to avoid collisions */
|
|
for (scale = 4; scale; scale /= 2) {
|
|
h = (struct pos *)malloc(scale * buckets * sizeof(struct pos));
|
|
if (h)
|
|
break;
|
|
}
|
|
|
|
if (!h)
|
|
return 0;
|
|
|
|
buckets = buckets * scale - 1;
|
|
|
|
/* clear the hash table */
|
|
for (i = 0; i <= buckets; i++) {
|
|
h[i].pos = INT_MAX;
|
|
h[i].len = 0;
|
|
}
|
|
|
|
/* add lines to the hash table chains */
|
|
for (i = bn - 1; i >= 0; i--) {
|
|
/* find the equivalence class */
|
|
for (j = b[i].h & buckets; h[j].pos != INT_MAX;
|
|
j = (j + 1) & buckets)
|
|
if (!cmp(b + i, b + h[j].pos))
|
|
break;
|
|
|
|
/* add to the head of the equivalence class */
|
|
b[i].n = h[j].pos;
|
|
b[i].e = j;
|
|
h[j].pos = i;
|
|
h[j].len++; /* keep track of popularity */
|
|
}
|
|
|
|
/* compute popularity threshold */
|
|
t = (bn >= 4000) ? bn / 1000 : bn + 1;
|
|
|
|
/* match items in a to their equivalence class in b */
|
|
for (i = 0; i < an; i++) {
|
|
/* find the equivalence class */
|
|
for (j = a[i].h & buckets; h[j].pos != INT_MAX;
|
|
j = (j + 1) & buckets)
|
|
if (!cmp(a + i, b + h[j].pos))
|
|
break;
|
|
|
|
a[i].e = j; /* use equivalence class for quick compare */
|
|
if (h[j].len <= t)
|
|
a[i].n = h[j].pos; /* point to head of match list */
|
|
else
|
|
a[i].n = INT_MAX; /* too popular */
|
|
}
|
|
|
|
/* discard hash tables */
|
|
free(h);
|
|
return 1;
|
|
}
|
|
|
|
static int longest_match(struct line *a, struct line *b, struct pos *pos,
|
|
int a1, int a2, int b1, int b2, int *omi, int *omj)
|
|
{
|
|
int mi = a1, mj = b1, mk = 0, mb = 0, i, j, k;
|
|
|
|
for (i = a1; i < a2; i++) {
|
|
/* skip things before the current block */
|
|
for (j = a[i].n; j < b1; j = b[j].n)
|
|
;
|
|
|
|
/* loop through all lines match a[i] in b */
|
|
for (; j < b2; j = b[j].n) {
|
|
/* does this extend an earlier match? */
|
|
if (i > a1 && j > b1 && pos[j - 1].pos == i - 1)
|
|
k = pos[j - 1].len + 1;
|
|
else
|
|
k = 1;
|
|
pos[j].pos = i;
|
|
pos[j].len = k;
|
|
|
|
/* best match so far? */
|
|
if (k > mk) {
|
|
mi = i;
|
|
mj = j;
|
|
mk = k;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (mk) {
|
|
mi = mi - mk + 1;
|
|
mj = mj - mk + 1;
|
|
}
|
|
|
|
/* expand match to include neighboring popular lines */
|
|
while (mi - mb > a1 && mj - mb > b1 &&
|
|
a[mi - mb - 1].e == b[mj - mb - 1].e)
|
|
mb++;
|
|
while (mi + mk < a2 && mj + mk < b2 &&
|
|
a[mi + mk].e == b[mj + mk].e)
|
|
mk++;
|
|
|
|
*omi = mi - mb;
|
|
*omj = mj - mb;
|
|
|
|
return mk + mb;
|
|
}
|
|
|
|
static void recurse(struct line *a, struct line *b, struct pos *pos,
|
|
int a1, int a2, int b1, int b2, struct hunklist *l)
|
|
{
|
|
int i, j, k;
|
|
|
|
/* find the longest match in this chunk */
|
|
k = longest_match(a, b, pos, a1, a2, b1, b2, &i, &j);
|
|
if (!k)
|
|
return;
|
|
|
|
/* and recurse on the remaining chunks on either side */
|
|
recurse(a, b, pos, a1, i, b1, j, l);
|
|
l->head->a1 = i;
|
|
l->head->a2 = i + k;
|
|
l->head->b1 = j;
|
|
l->head->b2 = j + k;
|
|
l->head++;
|
|
recurse(a, b, pos, i + k, a2, j + k, b2, l);
|
|
}
|
|
|
|
static struct hunklist diff(struct line *a, int an, struct line *b, int bn)
|
|
{
|
|
struct hunklist l;
|
|
struct hunk *curr;
|
|
struct pos *pos;
|
|
int t;
|
|
|
|
/* allocate and fill arrays */
|
|
t = equatelines(a, an, b, bn);
|
|
pos = (struct pos *)calloc(bn ? bn : 1, sizeof(struct pos));
|
|
/* we can't have more matches than lines in the shorter file */
|
|
l.head = l.base = (struct hunk *)malloc(sizeof(struct hunk) *
|
|
((an<bn ? an:bn) + 1));
|
|
|
|
if (pos && l.base && t) {
|
|
/* generate the matching block list */
|
|
recurse(a, b, pos, 0, an, 0, bn, &l);
|
|
l.head->a1 = l.head->a2 = an;
|
|
l.head->b1 = l.head->b2 = bn;
|
|
l.head++;
|
|
}
|
|
|
|
free(pos);
|
|
|
|
/* normalize the hunk list, try to push each hunk towards the end */
|
|
for (curr = l.base; curr != l.head; curr++) {
|
|
struct hunk *next = curr+1;
|
|
int shift = 0;
|
|
|
|
if (next == l.head)
|
|
break;
|
|
|
|
if (curr->a2 == next->a1)
|
|
while (curr->a2+shift < an && curr->b2+shift < bn
|
|
&& !cmp(a+curr->a2+shift, b+curr->b2+shift))
|
|
shift++;
|
|
else if (curr->b2 == next->b1)
|
|
while (curr->b2+shift < bn && curr->a2+shift < an
|
|
&& !cmp(b+curr->b2+shift, a+curr->a2+shift))
|
|
shift++;
|
|
if (!shift)
|
|
continue;
|
|
curr->b2 += shift;
|
|
next->b1 += shift;
|
|
curr->a2 += shift;
|
|
next->a1 += shift;
|
|
}
|
|
|
|
return l;
|
|
}
|
|
|
|
//--
|
|
// TODO: implement the r_diff_lines // we need to implement r_file_line_at (file, off);
|
|
R_API int r_diff_buffers_delta(RDiff *d, const ut8 *sa, int la, const ut8 *sb, int lb) {
|
|
RDiffOp dop;
|
|
struct line *al = NULL;
|
|
struct line *bl = NULL;
|
|
struct hunklist l = { NULL, NULL };
|
|
struct hunk *h;
|
|
int an, bn, offa, rlen, offb, len = 0;
|
|
int hits = -1;
|
|
|
|
an = splitlines ((const char *)sa, la, &al);
|
|
bn = splitlines ((const char*)sb, lb, &bl);
|
|
if (!al || !bl) {
|
|
eprintf ("bindiff_buffers: Out of memory.\n");
|
|
goto beach;
|
|
}
|
|
|
|
l = diff (al, an, bl, bn);
|
|
if (!l.head) {
|
|
eprintf ("bindiff_buffers: Out of memory.\n");
|
|
goto beach;
|
|
}
|
|
|
|
hits = la = lb = 0;
|
|
for (h = l.base; h != l.head; h++) {
|
|
if (h->a1 != la || h->b1 != lb) {
|
|
len = bl[h->b1].l - bl[lb].l;
|
|
offa = al[la].l - al->l;
|
|
offb = al[h->a1].l - al->l;
|
|
rlen = offb-offa;
|
|
|
|
if (d->callback) {
|
|
/* source file */
|
|
dop.a_off = offa;
|
|
dop.a_buf = (ut8 *)al[la].l;
|
|
dop.a_len = rlen;
|
|
|
|
/* destination file */
|
|
dop.b_off = offa; // XXX offb not used??
|
|
dop.b_buf = (ut8 *)bl[lb].l;
|
|
dop.b_len = len;
|
|
if (!d->callback (d, d->user, &dop))
|
|
break;
|
|
}
|
|
#if 0
|
|
if (rlen > 0) {
|
|
//printf ("Remove %d bytes at %d\n", rlen, offa);
|
|
printf ("r-%d @ 0x%"PFMT64x"\n", rlen, (ut64)offa);
|
|
}
|
|
printf ("e file.write=true\n"); // XXX
|
|
printf ("wx ");
|
|
for(i=0;i<len;i++)
|
|
printf ("%02x", bl[lb].l[i]);
|
|
printf (" @ 0x%"PFMT64x"\n", (ut64)offa);
|
|
rb += 12 + len;
|
|
#endif
|
|
}
|
|
la = h->a2;
|
|
lb = h->b2;
|
|
}
|
|
beach:
|
|
free (al);
|
|
free (bl);
|
|
free (l.base);
|
|
|
|
return hits;
|
|
}
|
|
|