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authorMatheus Izvekov <mizvekov@gmail.com>2010-01-18 03:57:17 (GMT)
committer Denys Vlasenko <vda.linux@googlemail.com>2010-01-18 03:57:17 (GMT)
commitd4a7728dc3b37e2956034f18fc26c04bc0aa2b0e (patch)
treeb08fde45be76ab4afb1c9af5df1177007c5b111e
parentf3fc9ac166d2413d331e3189a132a693608695ba (diff)
downloadbusybox-d4a7728dc3b37e2956034f18fc26c04bc0aa2b0e.tar.gz
busybox-d4a7728dc3b37e2956034f18fc26c04bc0aa2b0e.tar.bz2
diff: rewrite. much smaller and more correct
function old new delta diffreg 1815 3156 +1341 diff_main 860 1194 +334 read_token - 161 +161 skip_dir - 44 +44 seek_ft - 31 +31 fetch 362 392 +30 line_compar - 21 +21 add_to_dirlist 65 61 -4 print_only 16 - -16 skipline 51 - -51 newcand 85 - -85 asciifile 89 - -89 print_status 178 73 -105 make_temp 148 - -148 files_differ 168 - -168 get_recursive_dirlist 182 - -182 sort 226 - -226 prepare 283 - -283 change 283 - -283 do_diff 416 - -416 dump_unified_vec 457 - -457 check 1512 595 -917 ------------------------------------------------------------------------------ (add/remove: 4/12 grow/shrink: 3/3 up/down: 1962/-3430) Total: -1468 bytes Signed-off-by: Matheus Izvekov <mizvekov@gmail.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
-rw-r--r--editors/Config.in16
-rw-r--r--editors/diff.c1840
-rwxr-xr-xtestsuite/diff.tests3
3 files changed, 709 insertions, 1150 deletions
diff --git a/editors/Config.in b/editors/Config.in
index 7dbc9b6..e1285f4 100644
--- a/editors/Config.in
+++ b/editors/Config.in
@@ -35,14 +35,6 @@ config DIFF
differences between them in a form that can be given to
the patch command.
-config FEATURE_DIFF_BINARY
- bool "Enable checks for binary files"
- default y
- depends on DIFF
- help
- This option enables support for checking for binary files
- before a comparison is carried out.
-
config FEATURE_DIFF_DIR
bool "Enable directory support"
default y
@@ -51,14 +43,6 @@ config FEATURE_DIFF_DIR
This option enables support for directory and subdirectory
comparison.
-config FEATURE_DIFF_MINIMAL
- bool "Enable -d option to find smaller sets of changes"
- default n
- depends on DIFF
- help
- Enabling this option allows the use of -d to make diff
- try hard to find the smallest possible set of changes.
-
config ED
bool "ed"
default n
diff --git a/editors/diff.c b/editors/diff.c
index 745ef0a..af6917a 100644
--- a/editors/diff.c
+++ b/editors/diff.c
@@ -2,6 +2,7 @@
/*
* Mini diff implementation for busybox, adapted from OpenBSD diff.
*
+ * Copyright (C) 2010 by Matheus Izvekov <mizvekov@gmail.com>
* Copyright (C) 2006 by Robert Sullivan <cogito.ergo.cogito@hotmail.com>
* Copyright (c) 2003 Todd C. Miller <Todd.Miller@courtesan.com>
*
@@ -12,386 +13,310 @@
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
-#include "libbb.h"
-
-#define dbg_error_msg(...) ((void)0)
-//#define dbg_error_msg(...) bb_error_msg(__VA_ARGS__)
-
-// #define FSIZE_MAX 32768
-
-/* NOINLINEs added to prevent gcc from merging too much into diffreg()
- * (it bites more than it can (efficiently) chew). */
-
-/*
- * Output flags
- */
-enum {
- /* Print a header/footer between files */
- /* D_HEADER = 1, - unused */
- /* Treat file as empty (/dev/null) */
- D_EMPTY1 = 2 * ENABLE_FEATURE_DIFF_DIR,
- D_EMPTY2 = 4 * ENABLE_FEATURE_DIFF_DIR,
-};
-
/*
- * Status values for print_status() and diffreg() return values
- * Guide:
- * D_SAME - files are the same
- * D_DIFFER - files differ
- * D_BINARY - binary files differ
- * D_COMMON - subdirectory common to both dirs
- * D_ONLY - file only exists in one dir
- * D_ISDIR1 - path1 a dir, path2 a file
- * D_ISDIR2 - path1 a file, path2 a dir
- * D_ERROR - error occurred
- * D_SKIPPED1 - skipped path1 as it is a special file
- * D_SKIPPED2 - skipped path2 as it is a special file
+ * The following code uses an algorithm due to Harold Stone,
+ * which finds a pair of longest identical subsequences in
+ * the two files.
+ *
+ * The major goal is to generate the match vector J.
+ * J[i] is the index of the line in file1 corresponding
+ * to line i in file0. J[i] = 0 if there is no
+ * such line in file1.
+ *
+ * Lines are hashed so as to work in core. All potential
+ * matches are located by sorting the lines of each file
+ * on the hash (called "value"). In particular, this
+ * collects the equivalence classes in file1 together.
+ * Subroutine equiv replaces the value of each line in
+ * file0 by the index of the first element of its
+ * matching equivalence in (the reordered) file1.
+ * To save space equiv squeezes file1 into a single
+ * array member in which the equivalence classes
+ * are simply concatenated, except that their first
+ * members are flagged by changing sign.
+ *
+ * Next the indices that point into member are unsorted into
+ * array class according to the original order of file0.
+ *
+ * The cleverness lies in routine stone. This marches
+ * through the lines of file0, developing a vector klist
+ * of "k-candidates". At step i a k-candidate is a matched
+ * pair of lines x,y (x in file0, y in file1) such that
+ * there is a common subsequence of length k
+ * between the first i lines of file0 and the first y
+ * lines of file1, but there is no such subsequence for
+ * any smaller y. x is the earliest possible mate to y
+ * that occurs in such a subsequence.
+ *
+ * Whenever any of the members of the equivalence class of
+ * lines in file1 matable to a line in file0 has serial number
+ * less than the y of some k-candidate, that k-candidate
+ * with the smallest such y is replaced. The new
+ * k-candidate is chained (via pred) to the current
+ * k-1 candidate so that the actual subsequence can
+ * be recovered. When a member has serial number greater
+ * that the y of all k-candidates, the klist is extended.
+ * At the end, the longest subsequence is pulled out
+ * and placed in the array J by unravel
+ *
+ * With J in hand, the matches there recorded are
+ * checked against reality to assure that no spurious
+ * matches have crept in due to hashing. If they have,
+ * they are broken, and "jackpot" is recorded--a harmless
+ * matter except that a true match for a spuriously
+ * mated line may now be unnecessarily reported as a change.
+ *
+ * Much of the complexity of the program comes simply
+ * from trying to minimize core utilization and
+ * maximize the range of doable problems by dynamically
+ * allocating what is needed and reusing what is not.
+ * The core requirements for problems larger than somewhat
+ * are (in words) 2*length(file0) + length(file1) +
+ * 3*(number of k-candidates installed), typically about
+ * 6n words for files of length n.
*/
-#define D_SAME 0
-#define D_DIFFER (1 << 0)
-#define D_BINARY (1 << 1)
-#define D_COMMON (1 << 2)
-/*#define D_ONLY (1 << 3) - unused */
-#define D_ISDIR1 (1 << 4)
-#define D_ISDIR2 (1 << 5)
-#define D_ERROR (1 << 6)
-#define D_SKIPPED1 (1 << 7)
-#define D_SKIPPED2 (1 << 8)
-
-/* Command line options */
-#define FLAG_a (1 << 0)
-#define FLAG_b (1 << 1)
-#define FLAG_d (1 << 2)
-#define FLAG_i (1 << 3)
-#define FLAG_L (1 << 4)
-#define FLAG_N (1 << 5)
-#define FLAG_q (1 << 6)
-#define FLAG_r (1 << 7)
-#define FLAG_s (1 << 8)
-#define FLAG_S (1 << 9)
-#define FLAG_t (1 << 10)
-#define FLAG_T (1 << 11)
-#define FLAG_U (1 << 12)
-#define FLAG_w (1 << 13)
+#include "libbb.h"
-struct cand {
- int x;
- int y;
- int pred;
-};
+#if 0
+//#define dbg_error_msg(...) bb_error_msg(__VA_ARGS__)
+#else
+#define dbg_error_msg(...) ((void)0)
+#endif
-struct line {
- int serial;
- int value;
+enum { /* print_status() and diffreg() return values */
+ STATUS_SAME, /* files are the same */
+ STATUS_DIFFER, /* files differ */
+ STATUS_BINARY, /* binary files differ */
};
-/*
- * The following struct is used to record change information
- * doing a "context" or "unified" diff. (see routine "change" to
- * understand the highly mnemonic field names)
- */
-struct context_vec {
- int a; /* start line in old file */
- int b; /* end line in old file */
- int c; /* start line in new file */
- int d; /* end line in new file */
+enum { /* Commandline flags */
+ FLAG_a,
+ FLAG_b,
+ FLAG_d,
+ FLAG_i, /* unused */
+ FLAG_L, /* unused */
+ FLAG_N,
+ FLAG_q,
+ FLAG_r,
+ FLAG_s,
+ FLAG_S, /* unused */
+ FLAG_t,
+ FLAG_T,
+ FLAG_U, /* unused */
+ FLAG_w,
};
+#define FLAG(x) (1 << FLAG_##x)
-
-#define g_read_buf bb_common_bufsiz1
+/* We cache file position to avoid excessive seeking */
+typedef struct FILE_and_pos_t {
+ FILE *ft_fp;
+ off_t ft_pos;
+} FILE_and_pos_t;
struct globals {
- bool anychange;
smallint exit_status;
int opt_U_context;
- int context_idx;
- IF_FEATURE_DIFF_DIR(int dl_count;)
- IF_FEATURE_DIFF_DIR(char **dl;)
- char *opt_S_start;
- const char *label1;
- const char *label2;
- int *J; /* will be overlaid on class */
- int clen;
- int pref, suff; /* length of prefix and suffix */
- int nlen[2];
- int slen[2];
- int clistlen; /* the length of clist */
- struct cand *clist; /* merely a free storage pot for candidates */
- long *ixnew; /* will be overlaid on nfile[1] */
- long *ixold; /* will be overlaid on klist */
- struct line *nfile[2];
- struct line *sfile[2]; /* shortened by pruning common prefix/suffix */
- struct context_vec *context_vector;
- char *tempname1, *tempname2;
- struct stat stb1, stb2;
+ char *label[2];
+ struct stat stb[2];
};
#define G (*ptr_to_globals)
-#define anychange (G.anychange )
#define exit_status (G.exit_status )
#define opt_U_context (G.opt_U_context )
-#define context_idx (G.context_idx )
-#define dl_count (G.dl_count )
-#define dl (G.dl )
-#define opt_S_start (G.opt_S_start )
-#define label1 (G.label1 )
-#define label2 (G.label2 )
-#define J (G.J )
-#define clen (G.clen )
-#define pref (G.pref )
-#define suff (G.suff )
-#define nlen (G.nlen )
-#define slen (G.slen )
-#define clistlen (G.clistlen )
-#define clist (G.clist )
-#define ixnew (G.ixnew )
-#define ixold (G.ixold )
-#define nfile (G.nfile )
-#define sfile (G.sfile )
-#define context_vector (G.context_vector )
-#define stb1 (G.stb1 )
-#define stb2 (G.stb2 )
-#define tempname1 (G.tempname1 )
-#define tempname2 (G.tempname2 )
+#define label (G.label )
+#define stb (G.stb )
#define INIT_G() do { \
SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
opt_U_context = 3; \
- context_vector = xrealloc_vector(context_vector, 6, 0); \
} while (0)
+typedef int token_t;
-#if ENABLE_FEATURE_DIFF_DIR
-static void print_only(const char *path, const char *entry)
-{
- printf("Only in %s: %s\n", path, entry);
-}
-#endif
+enum {
+ /* Public */
+ TOK_EMPTY = 1 << 9, /* Line fully processed, you can proceed to the next */
+ TOK_EOF = 1 << 10, /* File ended */
+ /* Private (Only to be used by read_token() */
+ TOK_EOL = 1 << 11, /* we saw EOL (sticky) */
+ TOK_SPACE = 1 << 12, /* used -b code, means we are skipping spaces */
+ SHIFT_EOF = (sizeof(token_t)*8 - 8) - 1,
+ CHAR_MASK = 0x1ff, /* 8th bit is used to distinguish EOF from 0xff */
+};
+/* Restores full EOF from one 8th bit: */
+//#define TOK2CHAR(t) (((t) << SHIFT_EOF) >> SHIFT_EOF)
+/* We don't really need the above, we only need to have EOF != any_real_char: */
+#define TOK2CHAR(t) ((t) & CHAR_MASK)
-static void print_status(int val, char *_path1, char *_path2)
+static void seek_ft(FILE_and_pos_t *ft, off_t pos)
{
- /*const char *const _entry = entry ? entry : "";*/
- /*char *const _path1 = entry ? concat_path_file(path1, _entry) : path1;*/
- /*char *const _path2 = entry ? concat_path_file(path2, _entry) : path2;*/
-
- switch (val) {
-/* case D_ONLY:
- print_only(path1, entry);
- break;
-*/
- case D_COMMON:
- printf("Common subdirectories: %s and %s\n", _path1, _path2);
- break;
- case D_BINARY:
- printf("Binary files %s and %s differ\n", _path1, _path2);
- break;
- case D_DIFFER:
- if (option_mask32 & FLAG_q)
- printf("Files %s and %s differ\n", _path1, _path2);
- break;
- case D_SAME:
- if (option_mask32 & FLAG_s)
- printf("Files %s and %s are identical\n", _path1, _path2);
- break;
- case D_ISDIR1:
- printf("File %s is a %s while file %s is a %s\n",
- _path1, "directory", _path2, "regular file");
- break;
- case D_ISDIR2:
- printf("File %s is a %s while file %s is a %s\n",
- _path1, "regular file", _path2, "directory");
- break;
- case D_SKIPPED1:
- printf("File %s is not a regular file or directory and was skipped\n",
- _path1);
- break;
- case D_SKIPPED2:
- printf("File %s is not a regular file or directory and was skipped\n",
- _path2);
- break;
- }
-/*
- if (entry) {
- free(_path1);
- free(_path2);
+ if (ft->ft_pos != pos) {
+ ft->ft_pos = pos;
+ fseeko(ft->ft_fp, pos, SEEK_SET);
}
-*/
}
-
-/* Read line, return its nonzero hash. Return 0 if EOF.
- *
- * Hash function taken from Robert Sedgewick, Algorithms in C, 3d ed., p 578.
+/* Reads tokens from given fp, handling -b and -w flags
+ * The user must reset tok every line start
*/
-static ALWAYS_INLINE int fiddle_sum(int sum, int t)
+static int read_token(FILE_and_pos_t *ft, token_t tok)
{
- return sum * 127 + t;
-}
-static int readhash(FILE *fp)
-{
- int i, t;
- int sum;
-
- sum = 1;
- i = 0;
- if (!(option_mask32 & (FLAG_b | FLAG_w))) {
- while ((t = getc(fp)) != '\n') {
- if (t == EOF) {
- if (i == 0)
- return 0;
- break;
- }
- sum = fiddle_sum(sum, t);
- i = 1;
- }
- } else {
- int space = 0;
+ tok |= TOK_EMPTY;
+ while (!(tok & TOK_EOL)) {
+ bool is_space;
+ int t;
+
+ t = fgetc(ft->ft_fp);
+ if (t != EOF)
+ ft->ft_pos++;
+ is_space = (t == EOF || isspace(t));
+
+ /* If t == EOF (-1), set both TOK_EOF and TOK_EOL */
+ tok |= (t & (TOK_EOF + TOK_EOL));
+ /* Only EOL? */
+ if (t == '\n')
+ tok |= TOK_EOL;
+
+ if ((option_mask32 & FLAG(w)) && is_space)
+ continue;
- while (1) {
- t = getc(fp);
- switch (t) {
- case '\t':
- case '\r':
- case '\v':
- case '\f':
- case ' ':
- space = 1;
- continue;
- default:
- if (space && !(option_mask32 & FLAG_w)) {
- i = 1;
- space = 0;
- }
- sum = fiddle_sum(sum, t);
- i = 1;
- continue;
- case EOF:
- if (i == 0)
- return 0;
- /* FALLTHROUGH */
- case '\n':
- break;
+ /* Trim char value to low 9 bits */
+ t &= CHAR_MASK;
+
+ if (option_mask32 & FLAG(b)) {
+ /* Was prev char whitespace? */
+ if (tok & TOK_SPACE) { /* yes */
+ if (is_space) /* this one too, ignore it */
+ continue;
+ tok &= ~TOK_SPACE;
+ } else if (is_space) {
+ /* 1st whitespace char.
+ * Set TOK_SPACE and replace char by ' ' */
+ t = TOK_SPACE + ' ';
}
- break;
}
+ /* Clear EMPTY */
+ tok &= ~(TOK_EMPTY + CHAR_MASK);
+ /* Assign char value (low 9 bits) and maybe set TOK_SPACE */
+ tok |= t;
+ break;
}
- /*
- * There is a remote possibility that we end up with a zero sum.
- * Zero is used as an EOF marker, so return 1 instead.
- */
- return (sum == 0 ? 1 : sum);
+#if 0
+ bb_error_msg("fp:%p tok:%x '%c'%s%s%s%s", fp, tok, tok & 0xff
+ , tok & TOK_EOF ? " EOF" : ""
+ , tok & TOK_EOL ? " EOL" : ""
+ , tok & TOK_EMPTY ? " EMPTY" : ""
+ , tok & TOK_SPACE ? " SPACE" : ""
+ );
+#endif
+ return tok;
}
+struct cand {
+ int x;
+ int y;
+ int pred;
+};
-/* Our diff implementation is using seek.
- * When we meet non-seekable file, we must make a temp copy.
- */
-static char *make_temp(FILE *f, struct stat *sb)
+static int search(const int *c, int k, int y, const struct cand *list)
{
- char *name;
- int fd;
-
- if (S_ISREG(sb->st_mode) || S_ISBLK(sb->st_mode))
- return NULL;
- name = xstrdup("/tmp/difXXXXXX");
- fd = mkstemp(name);
- if (fd < 0)
- bb_perror_msg_and_die("mkstemp");
- if (bb_copyfd_eof(fileno(f), fd) < 0) {
- clean_up:
- unlink(name);
- xfunc_die(); /* error message is printed by bb_copyfd_eof */
- }
- fstat(fd, sb);
- close(fd);
- if (freopen(name, "r+", f) == NULL) {
- bb_perror_msg("freopen");
- goto clean_up;
- }
- return name;
-}
-
+ if (list[c[k]].y < y) /* quick look for typical case */
+ return k + 1;
-/*
- * Check to see if the given files differ.
- * Returns 0 if they are the same, 1 if different, and -1 on error.
- */
-static NOINLINE int files_differ(FILE *f1, FILE *f2)
-{
- size_t i, j;
-
- /* Prevent making copies for "/dev/null" (too common) */
- /* Deal with input from pipes etc */
- tempname1 = make_temp(f1, &stb1);
- tempname2 = make_temp(f2, &stb2);
- if (stb1.st_size != stb2.st_size) {
- return 1;
- }
- while (1) {
- i = fread(g_read_buf, 1, COMMON_BUFSIZE/2, f1);
- j = fread(g_read_buf + COMMON_BUFSIZE/2, 1, COMMON_BUFSIZE/2, f2);
- if (i != j)
- return 1;
- if (i == 0)
- return (ferror(f1) || ferror(f2)) ? -1 : 0;
- if (memcmp(g_read_buf,
- g_read_buf + COMMON_BUFSIZE/2, i) != 0)
- return 1;
+ for (int i = 0, j = k + 1;;) {
+ const int l = (i + j) >> 1;
+ if (l > i) {
+ const int t = list[c[l]].y;
+ if (t > y)
+ j = l;
+ else if (t < y)
+ i = l;
+ else
+ return l;
+ } else
+ return l + 1;
}
}
-
-static void prepare(int i, FILE *fp /*, off_t filesize*/)
+static unsigned isqrt(unsigned n)
{
- struct line *p;
- int h;
- size_t j, sz;
-
- rewind(fp);
-
- /*sz = (filesize <= FSIZE_MAX ? filesize : FSIZE_MAX) / 25;*/
- /*if (sz < 100)*/
- sz = 100;
-
- p = xmalloc((sz + 3) * sizeof(p[0]));
- j = 0;
- while ((h = readhash(fp)) != 0) { /* while not EOF */
- if (j == sz) {
- sz = sz * 3 / 2;
- p = xrealloc(p, (sz + 3) * sizeof(p[0]));
- }
- p[++j].value = h;
+ unsigned x = 1;
+ while (1) {
+ const unsigned y = x;
+ x = ((n / x) + x) >> 1;
+ if (x <= (y + 1) && x >= (y - 1))
+ return x;
}
- nlen[i] = j;
- nfile[i] = p;
}
-
-static void prune(void)
+static void stone(const int *a, int n, const int *b, int *J, int pref)
{
- int i, j;
-
- for (pref = 0; pref < nlen[0] && pref < nlen[1] &&
- nfile[0][pref + 1].value == nfile[1][pref + 1].value; pref++)
- continue;
- for (suff = 0; suff < nlen[0] - pref && suff < nlen[1] - pref &&
- nfile[0][nlen[0] - suff].value == nfile[1][nlen[1] - suff].value;
- suff++)
- continue;
- for (j = 0; j < 2; j++) {
- sfile[j] = nfile[j] + pref;
- slen[j] = nlen[j] - pref - suff;
- for (i = 0; i <= slen[j]; i++)
- sfile[j][i].serial = i;
+ const unsigned isq = isqrt(n);
+ const unsigned bound =
+ (option_mask32 & FLAG(d)) ? UINT_MAX : MAX(256, isq);
+ int clen = 1;
+ int clistlen = 100;
+ int k = 0;
+ struct cand *clist = xzalloc(clistlen * sizeof(clist[0]));
+ int *klist = xzalloc((n + 2) * sizeof(klist[0]));
+ /*clist[0] = (struct cand){0}; - xzalloc did it */
+ /*klist[0] = 0; */
+
+ for (struct cand cand = {1}; cand.x <= n; cand.x++) {
+ int j = a[cand.x], oldl = 0;
+ unsigned numtries = 0;
+ if (j == 0)
+ continue;
+ cand.y = -b[j];
+ cand.pred = klist[0];
+ do {
+ int l, tc;
+ if (cand.y <= clist[cand.pred].y)
+ continue;
+ l = search(klist, k, cand.y, clist);
+ if (l != oldl + 1)
+ cand.pred = klist[l - 1];
+ if (l <= k && clist[klist[l]].y <= cand.y)
+ continue;
+ if (clen == clistlen) {
+ clistlen = clistlen * 11 / 10;
+ clist = xrealloc(clist, clistlen * sizeof(clist[0]));
+ }
+ clist[clen] = cand;
+ tc = klist[l];
+ klist[l] = clen++;
+ if (l <= k) {
+ cand.pred = tc;
+ oldl = l;
+ numtries++;
+ } else {
+ k++;
+ break;
+ }
+ } while ((cand.y = b[++j]) > 0 && numtries < bound);
}
+ /* Unravel */
+ for (struct cand *q = clist + klist[k]; q->y; q = clist + q->pred)
+ J[q->x + pref] = q->y + pref;
+ free(klist);
+ free(clist);
}
+struct line {
+ /* 'serial' is not used in the begining, so we reuse it
+ * to store line offsets, thus reducing memory pressure
+ */
+ union {
+ unsigned serial;
+ off_t offset;
+ };
+ unsigned value;
+};
static void equiv(struct line *a, int n, struct line *b, int m, int *c)
{
- int i, j;
+ int i = 1, j = 1;
- i = j = 1;
while (i <= n && j <= m) {
if (a[i].value < b[j].value)
a[i++].value = 0;
@@ -414,286 +339,28 @@ static void equiv(struct line *a, int n, struct line *b, int m, int *c)
c[j] = -1;
}
-
-static int isqrt(int n)
-{
- int y, x;
-
- if (n == 0)
- return 0;
- x = 1;
- do {
- y = x;
- x = n / x;
- x += y;
- x /= 2;
- } while ((x - y) > 1 || (x - y) < -1);
-
- return x;
-}
-
-
-static int newcand(int x, int y, int pred)
+static void unsort(const struct line *f, int l, int *b)
{
- struct cand *q;
-
- if (clen == clistlen) {
- clistlen = clistlen * 11 / 10;
- clist = xrealloc(clist, clistlen * sizeof(struct cand));
- }
- q = clist + clen;
- q->x = x;
- q->y = y;
- q->pred = pred;
- return clen++;
-}
-
-
-static int search(int *c, int k, int y)
-{
- int i, j, l, t;
-
- if (clist[c[k]].y < y) /* quick look for typical case */
- return k + 1;
- i = 0;
- j = k + 1;
- while (1) {
- l = i + j;
- if ((l >>= 1) <= i)
- break;
- t = clist[c[l]].y;
- if (t > y)
- j = l;
- else if (t < y)
- i = l;
- else
- return l;
- }
- return l + 1;
-}
-
-
-static int stone(int *a, int n, int *b, int *c)
-{
- int i, k, y, j, l;
- int oldc, tc, oldl;
- unsigned numtries;
- int isq = isqrt(n);
-#if ENABLE_FEATURE_DIFF_MINIMAL
- const unsigned bound =
- (option_mask32 & FLAG_d) ? UINT_MAX : MAX(256, isq);
-#else
- const unsigned bound = MAX(256, isq);
-#endif
-
- k = 0;
- c[0] = newcand(0, 0, 0);
- for (i = 1; i <= n; i++) {
- j = a[i];
- if (j == 0)
- continue;
- y = -b[j];
- oldl = 0;
- oldc = c[0];
- numtries = 0;
- do {
- if (y <= clist[oldc].y)
- continue;
- l = search(c, k, y);
- if (l != oldl + 1)
- oldc = c[l - 1];
- if (l <= k) {
- if (clist[c[l]].y <= y)
- continue;
- tc = c[l];
- c[l] = newcand(i, y, oldc);
- oldc = tc;
- oldl = l;
- numtries++;
- } else {
- c[l] = newcand(i, y, oldc);
- k++;
- break;
- }
- } while ((y = b[++j]) > 0 && numtries < bound);
- }
- return k;
-}
-
-
-static void unravel(int p)
-{
- struct cand *q;
- int i;
-
- for (i = 0; i <= nlen[0]; i++)
- J[i] = i <= pref ? i : i > nlen[0] - suff ? i + nlen[1] - nlen[0] : 0;
- for (q = clist + p; q->y != 0; q = clist + q->pred)
- J[q->x + pref] = q->y + pref;
-}
-
-
-static void unsort(struct line *f, int l, int *b)
-{
- int *a, i;
-
- a = xmalloc((l + 1) * sizeof(int));
- for (i = 1; i <= l; i++)
+ int *a = xmalloc((l + 1) * sizeof(a[0]));
+ for (int i = 1; i <= l; i++)
a[f[i].serial] = f[i].value;
- for (i = 1; i <= l; i++)
+ for (int i = 1; i <= l; i++)
b[i] = a[i];
free(a);
}
-
-static int skipline(FILE *f)
-{
- int i, c;
-
- for (i = 1; (c = getc(f)) != '\n' && c != EOF; i++)
- continue;
- return i;
-}
-
-
-/*
- * Check does double duty:
- * 1. ferret out any fortuitous correspondences due
- * to confounding by hashing (which result in "jackpot")
- * 2. collect random access indexes to the two files
- */
-static NOINLINE void check(FILE *f1, FILE *f2)
-{
- int i, j, jackpot, c, d;
- long ctold, ctnew;
-
- rewind(f1);
- rewind(f2);
- j = 1;
- ixold[0] = ixnew[0] = 0;
- jackpot = 0;
- ctold = ctnew = 0;
- for (i = 1; i <= nlen[0]; i++) {
- if (J[i] == 0) {
- ixold[i] = ctold += skipline(f1);
- continue;
- }
- while (j < J[i]) {
- ixnew[j] = ctnew += skipline(f2);
- j++;
- }
- if (option_mask32 & (FLAG_b | FLAG_w | FLAG_i)) {
- while (1) {
- c = getc(f1);
- d = getc(f2);
- /*
- * GNU diff ignores a missing newline
- * in one file if bflag || wflag.
- */
- if ((option_mask32 & (FLAG_b | FLAG_w))
- && ((c == EOF && d == '\n') || (c == '\n' && d == EOF))
- ) {
- break;
- }
- ctold++;
- ctnew++;
- if ((option_mask32 & FLAG_b) && isspace(c) && isspace(d)) {
- do {
- if (c == '\n')
- break;
- ctold++;
- c = getc(f1);
- } while (isspace(c));
- do {
- if (d == '\n')
- break;
- ctnew++;
- d = getc(f2);
- } while (isspace(d));
- } else if (option_mask32 & FLAG_w) {
- while (isspace(c) && c != '\n') {
- c = getc(f1);
- ctold++;
- }
- while (isspace(d) && d != '\n') {
- d = getc(f2);
- ctnew++;
- }
- }
- if (c != d) {
- jackpot++;
- J[i] = 0;
- if (c != '\n' && c != EOF)
- ctold += skipline(f1);
- if (d != '\n' && c != EOF)
- ctnew += skipline(f2);
- break;
- }
- if (c == '\n' || c == EOF)
- break;
- }
- } else {
- while (1) {
- ctold++;
- ctnew++;
- c = getc(f1);
- d = getc(f2);
- if (c != d) {
- J[i] = 0;
- if (c != '\n' && c != EOF)
- ctold += skipline(f1);
-/* was buggy? "if (d != '\n' && c != EOF)" */
- if (d != '\n' && d != EOF)
- ctnew += skipline(f2);
- break;
- }
- if (c == '\n' || c == EOF)
- break;
- }
- }
- ixold[i] = ctold;
- ixnew[j] = ctnew;
- j++;
- }
- for (; j <= nlen[1]; j++)
- ixnew[j] = ctnew += skipline(f2);
-}
-
-
-/* shellsort CACM #201 */
-static void sort(struct line *a, int n)
+static int line_compar(const void *a, const void *b)
{
- struct line *ai, *aim, w;
- int j, m = 0, k;
-
- if (n == 0)
- return;
- for (j = 1; j <= n; j *= 2)
- m = 2 * j - 1;
- for (m /= 2; m != 0; m /= 2) {
- k = n - m;
- for (j = 1; j <= k; j++) {
- for (ai = &a[j]; ai > a; ai -= m) {
- aim = &ai[m];
- if (aim < ai)
- break; /* wraparound */
- if (aim->value > ai[0].value
- || (aim->value == ai[0].value && aim->serial > ai[0].serial)
- ) {
- break;
- }
- w.value = ai[0].value;
- ai[0].value = aim->value;
- aim->value = w.value;
- w.serial = ai[0].serial;
- ai[0].serial = aim->serial;
- aim->serial = w.serial;
- }
- }
- }
+#define l0 ((const struct line*)a)
+#define l1 ((const struct line*)b)
+ int r = l0->value - l1->value;
+ if (r)
+ return r;
+ return l0->serial - l1->serial;
+#undef l0
+#undef l1
}
-
static void uni_range(int a, int b)
{
if (a < b)
@@ -704,33 +371,23 @@ static void uni_range(int a, int b)
printf("%d,0", b);
}
-
-static void fetch(long *f, int a, int b, FILE *lb, int ch)
+static void fetch(FILE_and_pos_t *ft, const off_t *ix, int a, int b, int ch)
{
- int i, j, c, lastc, col, nc;
-
- if (a > b)
- return;
- for (i = a; i <= b; i++) {
- fseek(lb, f[i - 1], SEEK_SET);
- nc = f[i] - f[i - 1];
- if (ch != '\0') {
- putchar(ch);
- if (option_mask32 & FLAG_T)
- putchar('\t');
- }
- col = 0;
- for (j = 0, lastc = '\0'; j < nc; j++, lastc = c) {
- c = getc(lb);
+ for (int i = a; i <= b; i++) {
+ seek_ft(ft, ix[i - 1]);
+ putchar(ch);
+ if (option_mask32 & FLAG(T))
+ putchar('\t');
+ for (int j = 0, col = 0; j < ix[i] - ix[i - 1]; j++) {
+ int c = fgetc(ft->ft_fp);
if (c == EOF) {
printf("\n\\ No newline at end of file\n");
return;
}
- if (c == '\t' && (option_mask32 & FLAG_t)) {
- do {
- putchar(' ');
- } while (++col & 7);
- } else {
+ ft->ft_pos++;
+ if (c == '\t' && (option_mask32 & FLAG(t)))
+ do putchar(' '); while (++col & 7);
+ else {
putchar(c);
col++;
}
@@ -738,540 +395,477 @@ static void fetch(long *f, int a, int b, FILE *lb, int ch)
}
}
-
-#if ENABLE_FEATURE_DIFF_BINARY
-static int asciifile(FILE *f)
+/* Creates the match vector J, where J[i] is the index
+ * of the line in the new file corresponding to the line i
+ * in the old file. Lines start at 1 instead of 0, that value
+ * being used instead to denote no corresponding line.
+ * This vector is dynamically allocated and must be freed by the caller.
+ *
+ * * fp is an input parameter, where fp[0] and fp[1] are the open
+ * old file and new file respectively.
+ * * nlen is an output variable, where nlen[0] and nlen[1]
+ * gets the number of lines in the old and new file respectively.
+ * * ix is an output variable, where ix[0] and ix[1] gets
+ * assigned dynamically allocated vectors of the offsets of the lines
+ * of the old and new file respectively. These must be freed by the caller.
+ */
+static int *create_J(FILE_and_pos_t ft[2], int nlen[2], off_t *ix[2])
{
- int i, cnt;
-
- if (option_mask32 & FLAG_a)
- return 1;
- rewind(f);
- cnt = fread(g_read_buf, 1, COMMON_BUFSIZE, f);
- for (i = 0; i < cnt; i++) {
- if (!isprint_asciionly(g_read_buf[i])
- && !isspace(g_read_buf[i])
- ) {
- return 0;
+ int *J, slen[2], *class, *member;
+ struct line *nfile[2], *sfile[2];
+ int pref = 0, suff = 0;
+
+ /* Lines of both files are hashed, and in the process
+ * their offsets are stored in the array ix[fileno]
+ * where fileno == 0 points to the old file, and
+ * fileno == 1 points to the new one.
+ */
+ for (int i = 0; i < 2; i++) {
+ unsigned hash;
+ token_t tok;
+ size_t sz = 100;
+ nfile[i] = xmalloc((sz + 3) * sizeof(nfile[i][0]));
+ seek_ft(&ft[i], 0);
+
+ nlen[i] = 0;
+ /* We could zalloc nfile, but then zalloc starts showing in gprof at ~1% */
+ nfile[i][0].offset = 0;
+ goto start; /* saves code */
+ while (1) {
+ tok = read_token(&ft[i], tok);
+ if (!(tok & TOK_EMPTY)) {
+ /* Hash algorithm taken from Robert Sedgewick, Algorithms in C, 3d ed., p 578. */
+ hash = hash * 128 - hash + TOK2CHAR(tok);
+ continue;
+ }
+ if (nlen[i]++ == sz) {
+ sz = sz * 3 / 2;
+ nfile[i] = xrealloc(nfile[i], (sz + 3) * sizeof(nfile[i][0]));
+ }
+ /* line_compar needs hashes fit into positive int */
+ nfile[i][nlen[i]].value = hash & INT_MAX;
+ /* like ftello(ft[i].ft_fp) but faster (avoids lseek syscall) */
+ nfile[i][nlen[i]].offset = ft[i].ft_pos;
+ if (tok & TOK_EOF) {
+ /* EOF counts as a token, so we have to adjust it here */
+ nfile[i][nlen[i]].offset++;
+ break;
+ }
+start:
+ hash = tok = 0;
}
+ /* Exclude lone EOF line from the end of the file, to make fetch()'s job easier */
+ if (nfile[i][nlen[i]].offset - nfile[i][nlen[i] - 1].offset == 1)
+ nlen[i]--;
+ /* Now we copy the line offsets into ix */
+ ix[i] = xmalloc((nlen[i] + 2) * sizeof(ix[i][0]));
+ for (int j = 0; j < nlen[i] + 1; j++)
+ ix[i][j] = nfile[i][j].offset;
+ }
+
+ /* lenght of prefix and suffix is calculated */
+ for (; pref < nlen[0] && pref < nlen[1] &&
+ nfile[0][pref + 1].value == nfile[1][pref + 1].value;
+ pref++);
+ for (; suff < nlen[0] - pref && suff < nlen[1] - pref &&
+ nfile[0][nlen[0] - suff].value == nfile[1][nlen[1] - suff].value;
+ suff++);
+ /* Arrays are pruned by the suffix and prefix lenght,
+ * the result being sorted and stored in sfile[fileno],
+ * and their sizes are stored in slen[fileno]
+ */
+ for (int j = 0; j < 2; j++) {
+ sfile[j] = nfile[j] + pref;
+ slen[j] = nlen[j] - pref - suff;
+ for (int i = 0; i <= slen[j]; i++)
+ sfile[j][i].serial = i;
+ qsort(sfile[j] + 1, slen[j], sizeof(*sfile[j]), line_compar);
}
- return 1;
-}
-#else
-#define asciifile(f) 1
-#endif
-
-
-/* dump accumulated "unified" diff changes */
-static void dump_unified_vec(FILE *f1, FILE *f2)
-{
- struct context_vec *cvp = context_vector;
- int lowa, upb, lowc, upd;
- int a, b, c, d;
- char ch;
-
- if (context_idx < 0)
- return;
-
- dbg_error_msg("dumping %d context_vecs", context_idx+1);
-
- b = d = 0; /* gcc */
- lowa = MAX(1, cvp->a - opt_U_context);
- upb = MIN(nlen[0], context_vector[context_idx].b + opt_U_context);
- lowc = MAX(1, cvp->c - opt_U_context);
- upd = MIN(nlen[1], context_vector[context_idx].d + opt_U_context);
-
- printf("@@ -");
- uni_range(lowa, upb);
- printf(" +");
- uni_range(lowc, upd);
- printf(" @@\n");
-
- /*
- * Output changes in "unified" diff format--the old and new lines
- * are printed together.
+ /* nfile arrays are reused to reduce memory pressure
+ * The #if zeroed out section performs the same task as the
+ * one in the #else section.
+ * Peak memory usage is higher, but one array copy is avoided
+ * by not using unsort()
*/
- for (; cvp <= &context_vector[context_idx]; cvp++) {
- a = cvp->a;
- b = cvp->b;
- c = cvp->c;
- d = cvp->d;
-
- /*
- * c: both new and old changes
- * d: only changes in the old file
- * a: only changes in the new file
- */
- if (a <= b && c <= d)
- ch = 'c';
- else
- ch = (a <= b) ? 'd' : 'a';
#if 0
- switch (ch) {
- case 'c':
-// fetch() seeks!
- fetch(ixold, lowa, a - 1, f1, ' ');
- fetch(ixold, a, b, f1, '-');
- fetch(ixnew, c, d, f2, '+');
- break;
- case 'd':
- fetch(ixold, lowa, a - 1, f1, ' ');
- fetch(ixold, a, b, f1, '-');
- break;
- case 'a':
- fetch(ixnew, lowc, c - 1, f2, ' ');
- fetch(ixnew, c, d, f2, '+');
- break;
- }
+ member = xmalloc((slen[1] + 2) * sizeof(member[0]));
+ equiv(sfile[0], slen[0], sfile[1], slen[1], member);
+ free(nfile[1]);
+
+ class = xmalloc((slen[0] + 1) * sizeof(class[0]));
+ for (int i = 1; i <= slen[0]; i++) /* Unsorting */
+ class[sfile[0][i].serial] = sfile[0][i].value;
+ free(nfile[0]);
#else
- if (ch == 'c' || ch == 'd') {
- fetch(ixold, lowa, a - 1, f1, ' ');
- fetch(ixold, a, b, f1, '-');
- }
- if (ch == 'a')
- fetch(ixnew, lowc, c - 1, f2, ' ');
- if (ch == 'c' || ch == 'a')
- fetch(ixnew, c, d, f2, '+');
-#endif
- lowa = b + 1;
- lowc = d + 1;
- }
- fetch(ixnew, d + 1, upd, f2, ' ');
+ member = (int *)nfile[1];
+ equiv(sfile[0], slen[0], sfile[1], slen[1], member);
+ member = xrealloc(member, (slen[1] + 2) * sizeof(member[0]));
- context_idx = -1;
-}
+ class = (int *)nfile[0];
+ unsort(sfile[0], slen[0], (int *)nfile[0]);
+ class = xrealloc(class, (slen[0] + 2) * sizeof(class[0]));
+#endif
+ J = xmalloc((nlen[0] + 2) * sizeof(J[0]));
+ /* The elements of J which fall inside the prefix and suffix regions
+ * are marked as unchanged, while the ones which fall outside
+ * are initialized with 0 (no matches), so that function stone can
+ * then assign them their right values
+ */
+ for (int i = 0, delta = nlen[1] - nlen[0]; i <= nlen[0]; i++)
+ J[i] = i <= pref ? i :
+ i > (nlen[0] - suff) ? (i + delta) : 0;
+ /* Here the magic is performed */
+ stone(class, slen[0], member, J, pref);
+ J[nlen[0] + 1] = nlen[1] + 1;
+ free(class);
+ free(member);
-static void print_header(const char *file1, const char *file2)
-{
- if (label1)
- printf("--- %s\n", label1);
- else
- printf("--- %s\t%s", file1, ctime(&stb1.st_mtime));
- if (label2)
- printf("+++ %s\n", label2);
- else
- printf("+++ %s\t%s", file2, ctime(&stb2.st_mtime));
-}
+ /* Both files are rescanned, in an effort to find any lines
+ * which, due to limitations intrinsic to any hashing algorithm,
+ * are different but ended up confounded as the same
+ */
+ for (int i = 1; i <= nlen[0]; i++) {
+ if (!J[i])
+ continue;
+ seek_ft(&ft[0], ix[0][i - 1]);
+ seek_ft(&ft[1], ix[1][J[i] - 1]);
-/*
- * Indicate that there is a difference between lines a and b of the from file
- * to get to lines c to d of the to file. If a is greater than b then there
- * are no lines in the from file involved and this means that there were
- * lines appended (beginning at b). If c is greater than d then there are
- * lines missing from the to file.
- */
-static void change(const char *file1, FILE *f1, const char *file2, FILE *f2,
- int a, int b, int c, int d)
-{
- if ((a > b && c > d) || (option_mask32 & FLAG_q)) {
-//compat BUG: "diff -ub F1 F2" will output nothing, but will exit 1
-//if F1 and F2 differ only in whitespace. "standard" diff exits 0.
-//This is the place where this erroneous exitcode is set:
- dbg_error_msg("%d: abcd:%d,%d,%d,%d, anychange=1", __LINE__, a,b,c,d);
- anychange = 1;
- return;
- }
+ for (int j = J[i]; i <= nlen[0] && J[i] == j; i++, j++) {
+ token_t tok0 = 0, tok1 = 0;
+ do {
+ tok0 = read_token(&ft[0], tok0);
+ tok1 = read_token(&ft[1], tok1);
- if (anychange == 0) {
- /*
- * Print the context/unidiff header first time through.
- */
- print_header(file1, file2);
- } else if (a > context_vector[context_idx].b + (2 * opt_U_context) + 1
- && c > context_vector[context_idx].d + (2 * opt_U_context) + 1
- ) {
- /*
- * If this change is more than 'context' lines from the
- * previous change, dump the record and reset it.
- */
-// dump_unified_vec() seeks!
- dump_unified_vec(f1, f2);
+ if (((tok0 ^ tok1) & TOK_EMPTY) != 0 /* one is empty (not both) */
+ || (!(tok0 & TOK_EMPTY) && TOK2CHAR(tok0) != TOK2CHAR(tok1)))
+ J[i] = 0; /* Break the correspondence */
+ } while (!(tok0 & tok1 & TOK_EMPTY));
+ }
}
- context_idx++;
- context_vector = xrealloc_vector(context_vector, 6, context_idx);
- context_vector[context_idx].a = a;
- context_vector[context_idx].b = b;
- context_vector[context_idx].c = c;
- context_vector[context_idx].d = d;
- dbg_error_msg("new context_vec[%d]:%d,%d,%d,%d", context_idx, a,b,c,d);
- anychange = 1;
-}
-
-static void output(const char *file1, FILE *f1, const char *file2, FILE *f2)
-{
- /* Note that j0 and j1 can't be used as they are defined in math.h.
- * This also allows the rather amusing variable 'j00'... */
- int m, i0, i1, j00, j01;
-
- rewind(f1);
- rewind(f2);
- m = nlen[0];
- J[0] = 0;
- J[m + 1] = nlen[1] + 1;
- for (i0 = 1; i0 <= m; i0 = i1 + 1) {
- while (i0 <= m && J[i0] == J[i0 - 1] + 1)
- i0++;
- j00 = J[i0 - 1] + 1;
- i1 = i0 - 1;
- while (i1 < m && J[i1 + 1] == 0)
- i1++;
- j01 = J[i1 + 1] - 1;
- J[i1] = j01;
-// change() seeks!
- change(file1, f1, file2, f2, i0, i1, j00, j01);
- }
- if (m == 0) {
-// change() seeks!
- change(file1, f1, file2, f2, 1, 0, 1, nlen[1]);
- }
- if (anychange != 0 && !(option_mask32 & FLAG_q)) {
-// dump_unified_vec() seeks!
- dump_unified_vec(f1, f2);
- }
+ return J;
}
/*
- * The following code uses an algorithm due to Harold Stone,
- * which finds a pair of longest identical subsequences in
- * the two files.
- *
- * The major goal is to generate the match vector J.
- * J[i] is the index of the line in file1 corresponding
- * to line i in file0. J[i] = 0 if there is no
- * such line in file1.
- *
- * Lines are hashed so as to work in core. All potential
- * matches are located by sorting the lines of each file
- * on the hash (called "value"). In particular, this
- * collects the equivalence classes in file1 together.
- * Subroutine equiv replaces the value of each line in
- * file0 by the index of the first element of its
- * matching equivalence in (the reordered) file1.
- * To save space equiv squeezes file1 into a single
- * array member in which the equivalence classes
- * are simply concatenated, except that their first
- * members are flagged by changing sign.
- *
- * Next the indices that point into member are unsorted into
- * array class according to the original order of file0.
- *
- * The cleverness lies in routine stone. This marches
- * through the lines of file0, developing a vector klist
- * of "k-candidates". At step i a k-candidate is a matched
- * pair of lines x,y (x in file0, y in file1) such that
- * there is a common subsequence of length k
- * between the first i lines of file0 and the first y
- * lines of file1, but there is no such subsequence for
- * any smaller y. x is the earliest possible mate to y
- * that occurs in such a subsequence.
- *
- * Whenever any of the members of the equivalence class of
- * lines in file1 matable to a line in file0 has serial number
- * less than the y of some k-candidate, that k-candidate
- * with the smallest such y is replaced. The new
- * k-candidate is chained (via pred) to the current
- * k-1 candidate so that the actual subsequence can
- * be recovered. When a member has serial number greater
- * that the y of all k-candidates, the klist is extended.
- * At the end, the longest subsequence is pulled out
- * and placed in the array J by unravel
- *
- * With J in hand, the matches there recorded are
- * checked against reality to assure that no spurious
- * matches have crept in due to hashing. If they have,
- * they are broken, and "jackpot" is recorded--a harmless
- * matter except that a true match for a spuriously
- * mated line may now be unnecessarily reported as a change.
- *
- * Much of the complexity of the program comes simply
- * from trying to minimize core utilization and
- * maximize the range of doable problems by dynamically
- * allocating what is needed and reusing what is not.
- * The core requirements for problems larger than somewhat
- * are (in words) 2*length(file0) + length(file1) +
- * 3*(number of k-candidates installed), typically about
- * 6n words for files of length n.
+ * The following struct is used to record change information
+ * doing a "context" or "unified" diff.
*/
-/* NB: files can be not REGular. The only sure thing that they
- * are not both DIRectories. */
-static unsigned diffreg(const char *file1, const char *file2, int flags)
+struct context_vec {
+ int a; /* start line in old file */
+ int b; /* end line in old file */
+ int c; /* start line in new file */
+ int d; /* end line in new file */
+};
+
+static bool diff(FILE_and_pos_t ft[2], char *file[2])
{
- int *member; /* will be overlaid on nfile[1] */
- int *class; /* will be overlaid on nfile[0] */
- int *klist; /* will be overlaid on nfile[0] after class */
- FILE *f1;
- FILE *f2;
- unsigned rval;
- int i;
-
- anychange = 0;
- context_idx = -1;
- tempname1 = tempname2 = NULL;
-
- /* Is any of them a directory? Then it's simple */
- if (S_ISDIR(stb1.st_mode) != S_ISDIR(stb2.st_mode))
- return (S_ISDIR(stb1.st_mode) ? D_ISDIR1 : D_ISDIR2);
-
- /* None of them are directories */
- rval = D_SAME;
-
- if (flags & D_EMPTY1)
- /* can't be stdin, but xfopen_stdin() is smaller code */
- file1 = bb_dev_null;
- f1 = xfopen_stdin(file1);
- if (flags & D_EMPTY2)
- file2 = bb_dev_null;
- f2 = xfopen_stdin(file2);
-
- /* NB: if D_EMPTY1/2 is set, other file is always a regular file,
- * not pipe/fifo/chardev/etc - D_EMPTY is used by "diff -r" only,
- * and it never diffs non-ordinary files in subdirs. */
- if (!(flags & (D_EMPTY1 | D_EMPTY2))) {
- /* Quick check whether they are different */
- /* NB: copies non-REG files to tempfiles and fills tempname1/2 */
- i = files_differ(f1, f2);
- if (i != 1) { /* not different? */
- if (i != 0) /* error? */
- exit_status |= 2;
- goto closem;
- }
- }
+ int nlen[2];
+ off_t *ix[2];
+ int *J = create_J(ft, nlen, ix);
- if (!asciifile(f1) || !asciifile(f2)) {
- rval = D_BINARY;
- exit_status |= 1;
- goto closem;
- }
+ bool anychange = false;
+ struct context_vec *vec = NULL;
+ int idx = -1, i = 1;
-// Rewind inside!
- prepare(0, f1 /*, stb1.st_size*/);
- prepare(1, f2 /*, stb2.st_size*/);
- prune();
- sort(sfile[0], slen[0]);
- sort(sfile[1], slen[1]);
+ do {
+ while (1) {
+ struct context_vec v;
- member = (int *) nfile[1];
- equiv(sfile[0], slen[0], sfile[1], slen[1], member);
-//TODO: xrealloc_vector?
- member = xrealloc(member, (slen[1] + 2) * sizeof(int));
-
- class = (int *) nfile[0];
- unsort(sfile[0], slen[0], class);
- class = xrealloc(class, (slen[0] + 2) * sizeof(int));
-
- klist = xmalloc((slen[0] + 2) * sizeof(int));
- clen = 0;
- clistlen = 100;
- clist = xmalloc(clistlen * sizeof(struct cand));
- i = stone(class, slen[0], member, klist);
- free(member);
- free(class);
+ for (v.a = i; v.a <= nlen[0] && J[v.a] == J[v.a - 1] + 1; v.a++)
+ continue;
+ v.c = J[v.a - 1] + 1;
- J = xrealloc(J, (nlen[0] + 2) * sizeof(int));
- unravel(klist[i]);
- free(clist);
- free(klist);
+ for (v.b = v.a - 1; v.b < nlen[0] && !J[v.b + 1]; v.b++)
+ continue;
+ v.d = J[v.b + 1] - 1;
+ /*
+ * Indicate that there is a difference between lines a and b of the 'from' file
+ * to get to lines c to d of the 'to' file. If a is greater than b then there
+ * are no lines in the 'from' file involved and this means that there were
+ * lines appended (beginning at b). If c is greater than d then there are
+ * lines missing from the 'to' file.
+ */
+ if (v.a <= v.b || v.c <= v.d) {
+ /*
+ * If this change is more than 'context' lines from the
+ * previous change, dump the record and reset it.
+ */
+ if (idx >= 0
+ && v.a > vec[idx].b + (2 * opt_U_context) + 1
+ && v.c > vec[idx].d + (2 * opt_U_context) + 1
+ ) {
+ break;
+ }
+ vec = xrealloc_vector(vec, 6, ++idx);
+ vec[idx] = v;
+ }
+
+ i = v.b + 1;
+ if (i > nlen[0])
+ break;
+ J[v.b] = v.d;
+ }
+ if (idx < 0)
+ continue;
+ if (!(option_mask32 & FLAG(q))) {
+ struct context_vec *cvp = vec;
+ int lowa = MAX(1, cvp->a - opt_U_context);
+ int upb = MIN(nlen[0], vec[idx].b + opt_U_context);
+ int lowc = MAX(1, cvp->c - opt_U_context);
+ int upd = MIN(nlen[1], vec[idx].d + opt_U_context);
+
+ if (!anychange) {
+ /* Print the context/unidiff header first time through */
+ printf("--- %s\n", label[0] ?: file[0]);
+ printf("+++ %s\n", label[1] ?: file[1]);
+ }
- ixold = xrealloc(ixold, (nlen[0] + 2) * sizeof(long));
- ixnew = xrealloc(ixnew, (nlen[1] + 2) * sizeof(long));
-// Rewind inside!
- check(f1, f2);
-// Rewind inside!
- output(file1, f1, file2, f2);
+ printf("@@ -");
+ uni_range(lowa, upb);
+ printf(" +");
+ uni_range(lowc, upd);
+ printf(" @@\n");
- closem:
- if (anychange) {
- exit_status |= 1;
- dbg_error_msg("exit_status|=1 = %d", exit_status);
- if (rval == D_SAME)
- rval = D_DIFFER;
- }
- fclose_if_not_stdin(f1);
- fclose_if_not_stdin(f2);
- if (tempname1) {
- unlink(tempname1);
- free(tempname1);
- }
- if (tempname2) {
- unlink(tempname2);
- free(tempname2);
- }
- return rval;
+ /*
+ * Output changes in "unified" diff format--the old and new lines
+ * are printed together.
+ */
+ while (1) {
+ bool end = cvp > &vec[idx];
+ fetch(&ft[0], ix[0], lowa, end ? upb : cvp->a - 1, ' ');
+ if (end)
+ break;
+ fetch(&ft[0], ix[0], cvp->a, cvp->b, '-');
+ fetch(&ft[1], ix[1], cvp->c, cvp->d, '+');
+ lowa = cvp++->b + 1;
+ }
+ }
+ idx = -1;
+ anychange = true;
+ } while (i <= nlen[0]);
+
+ free(vec);
+ free(ix[0]);
+ free(ix[1]);
+ free(J);
+ return anychange;
}
-
-#if ENABLE_FEATURE_DIFF_DIR
-static void do_diff(char *dir1, char *path1, char *dir2, char *path2)
+static int diffreg(char *file[2])
{
- int flags = 0; /*D_HEADER;*/
- int val;
- char *fullpath1 = NULL; /* if -N */
- char *fullpath2 = NULL;
-
- if (path1)
- fullpath1 = concat_path_file(dir1, path1);
- if (path2)
- fullpath2 = concat_path_file(dir2, path2);
-
- if (!fullpath1 || stat(fullpath1, &stb1) != 0) {
- flags |= D_EMPTY1;
- memset(&stb1, 0, sizeof(stb1));
- if (path2) {
- free(fullpath1);
- fullpath1 = concat_path_file(dir1, path2);
+ FILE_and_pos_t ft[2];
+ bool binary = false, differ = false;
+ int status = STATUS_SAME;
+
+ for (int i = 0; i < 2; i++) {
+ int fd = open_or_warn_stdin(file[i]);
+ if (fd == -1)
+ xfunc_die();
+ /* Our diff implementation is using seek.
+ * When we meet non-seekable file, we must make a temp copy.
+ */
+ ft[i].ft_pos = 0;
+ if (lseek(fd, 0, SEEK_SET) == -1 && errno == ESPIPE) {
+ char name[] = "/tmp/difXXXXXX";
+ int fd_tmp = mkstemp(name);
+ if (fd_tmp < 0)
+ bb_perror_msg_and_die("mkstemp");
+ unlink(name);
+ ft[i].ft_pos = bb_copyfd_eof(fd, fd_tmp);
+ /* error message is printed by bb_copyfd_eof */
+ if (ft[i].ft_pos < 0)
+ xfunc_die();
+ fstat(fd, &stb[i]);
+ if (fd) /* Prevents closing of stdin */
+ close(fd);
+ fd = fd_tmp;
}
+ ft[i].ft_fp = fdopen(fd, "r");
}
- if (!fullpath2 || stat(fullpath2, &stb2) != 0) {
- flags |= D_EMPTY2;
- memset(&stb2, 0, sizeof(stb2));
- stb2.st_mode = stb1.st_mode;
- if (path1) {
- free(fullpath2);
- fullpath2 = concat_path_file(dir2, path1);
+
+ while (1) {
+ const size_t sz = COMMON_BUFSIZE / 2;
+ char *const buf0 = bb_common_bufsiz1;
+ char *const buf1 = buf0 + sz;
+ int i, j;
+ i = fread(buf0, 1, sz, ft[0].ft_fp);
+ ft[0].ft_pos += i;
+ j = fread(buf1, 1, sz, ft[1].ft_fp);
+ ft[1].ft_pos += j;
+ if (i != j) {
+ differ = true;
+ i = MIN(i, j);
+ }
+ if (i == 0)
+ break;
+ for (int k = 0; k < i; k++) {
+ if (!buf0[k] || !buf1[k])
+ binary = true;
+ if (buf0[k] != buf1[k])
+ differ = true;
}
}
-
- if (stb1.st_mode == 0)
- stb1.st_mode = stb2.st_mode;
-
- if (S_ISDIR(stb1.st_mode) && S_ISDIR(stb2.st_mode)) {
- printf("Common subdirectories: %s and %s\n", fullpath1, fullpath2);
- goto ret;
+ if (differ) {
+ if (binary && !(option_mask32 & FLAG(a)))
+ status = STATUS_BINARY;
+ else if (diff(ft, file))
+ status = STATUS_DIFFER;
}
+ if (status != STATUS_SAME)
+ exit_status |= 1;
- if (!S_ISREG(stb1.st_mode) && !S_ISDIR(stb1.st_mode))
- val = D_SKIPPED1;
- else if (!S_ISREG(stb2.st_mode) && !S_ISDIR(stb2.st_mode))
- val = D_SKIPPED2;
- else {
- /* Both files are either REGular or DIRectories */
- val = diffreg(fullpath1, fullpath2, flags);
- }
+ fclose_if_not_stdin(ft[0].ft_fp);
+ fclose_if_not_stdin(ft[1].ft_fp);
- print_status(val, fullpath1, fullpath2 /*, NULL*/);
- ret:
- free(fullpath1);
- free(fullpath2);
+ return status;
}
-#endif
+static void print_status(int status, char *path[2])
+{
+ switch (status) {
+ case STATUS_BINARY:
+ case STATUS_DIFFER:
+ if ((option_mask32 & FLAG(q)) || status == STATUS_BINARY)
+ printf("Files %s and %s differ\n", path[0], path[1]);
+ break;
+ case STATUS_SAME:
+ if (option_mask32 & FLAG(s))
+ printf("Files %s and %s are identical\n", path[0], path[1]);
+ break;
+ }
+}
#if ENABLE_FEATURE_DIFF_DIR
+struct dlist {
+ size_t len;
+ int s, e;
+ char **dl;
+};
+
/* This function adds a filename to dl, the directory listing. */
static int FAST_FUNC add_to_dirlist(const char *filename,
struct stat *sb UNUSED_PARAM,
- void *userdata,
- int depth UNUSED_PARAM)
+ void *userdata, int depth UNUSED_PARAM)
{
- dl = xrealloc_vector(dl, 5, dl_count);
- dl[dl_count] = xstrdup(filename + (int)(ptrdiff_t)userdata);
- dl_count++;
+ struct dlist *const l = userdata;
+ l->dl = xrealloc_vector(l->dl, 6, l->e);
+ /* + 1 skips "/" after dirname */
+ l->dl[l->e] = xstrdup(filename + l->len + 1);
+ l->e++;
return TRUE;
}
-
-/* This returns a sorted directory listing. */
-static char **get_recursive_dirlist(char *path)
+/* If recursion is not set, this function adds the directory
+ * to the list and prevents recursive_action from recursing into it.
+ */
+static int FAST_FUNC skip_dir(const char *filename,
+ struct stat *sb, void *userdata,
+ int depth)
{
- dl_count = 0;
- dl = xzalloc(sizeof(dl[0]));
-
- /* We need to trim root directory prefix.
- * Using void *userdata to specify its length,
- * add_to_dirlist will remove it. */
- if (option_mask32 & FLAG_r) {
- recursive_action(path, ACTION_RECURSE|ACTION_FOLLOWLINKS,
- add_to_dirlist, /* file_action */
- NULL, /* dir_action */
- (void*)(ptrdiff_t)(strlen(path) + 1),
- 0);
- } else {
- DIR *dp;
- struct dirent *ep;
-
- dp = warn_opendir(path);
- while ((ep = readdir(dp))) {
- if (!strcmp(ep->d_name, "..") || LONE_CHAR(ep->d_name, '.'))
- continue;
- add_to_dirlist(ep->d_name, NULL, (void*)(int)0, 0);
- }
- closedir(dp);
+ if (!(option_mask32 & FLAG(r)) && depth) {
+ add_to_dirlist(filename, sb, userdata, depth);
+ return SKIP;
}
-
- /* Sort dl alphabetically. */
- qsort_string_vector(dl, dl_count);
-
- dl[dl_count] = NULL;
- return dl;
+ return TRUE;
}
-
-static void diffdir(char *p1, char *p2)
+static void diffdir(char *p[2], const char *s_start)
{
- char **dirlist1, **dirlist2;
- char *dp1, *dp2;
- int pos;
-
- /* Check for trailing slashes. */
- dp1 = last_char_is(p1, '/');
- if (dp1 != NULL)
- *dp1 = '\0';
- dp2 = last_char_is(p2, '/');
- if (dp2 != NULL)
- *dp2 = '\0';
-
- /* Get directory listings for p1 and p2. */
- dirlist1 = get_recursive_dirlist(p1);
- dirlist2 = get_recursive_dirlist(p2);
-
- /* If -S was set, find the starting point. */
- if (opt_S_start) {
- while (*dirlist1 != NULL && strcmp(*dirlist1, opt_S_start) < 0)
- dirlist1++;
- while (*dirlist2 != NULL && strcmp(*dirlist2, opt_S_start) < 0)
- dirlist2++;
- if ((*dirlist1 == NULL) || (*dirlist2 == NULL))
- bb_error_msg(bb_msg_invalid_arg, "NULL", "-S");
+ struct dlist list[2];
+
+ memset(&list, 0, sizeof(list));
+ for (int i = 0; i < 2; i++) {
+ /*list[i].s = list[i].e = 0; - memset did it */
+ /*list[i].dl = NULL; */
+
+ /* We need to trim root directory prefix.
+ * Using list.len to specify its length,
+ * add_to_dirlist will remove it. */
+ list[i].len = strlen(p[i]);
+ recursive_action(p[i], ACTION_RECURSE | ACTION_FOLLOWLINKS,
+ add_to_dirlist, skip_dir, &list[i], 0);
+ /* Sort dl alphabetically.
+ * GNU diff does this ignoring any number of trailing dots.
+ * We don't, so for us dotted files almost always are
+ * first on the list.
+ */
+ qsort_string_vector(list[i].dl, list[i].e);
+ /* If -S was set, find the starting point. */
+ if (!s_start)
+ continue;
+ while (list[i].s < list[i].e && strcmp(list[i].dl[list[i].s], s_start) < 0)
+ list[i].s++;
}
-
/* Now that both dirlist1 and dirlist2 contain sorted directory
* listings, we can start to go through dirlist1. If both listings
* contain the same file, then do a normal diff. Otherwise, behaviour
* is determined by whether the -N flag is set. */
- while (*dirlist1 != NULL || *dirlist2 != NULL) {
- dp1 = *dirlist1;
- dp2 = *dirlist2;
- pos = dp1 == NULL ? 1 : (dp2 == NULL ? -1 : strcmp(dp1, dp2));
+ while (1) {
+ char *dp[2];
+ int pos;
+ int k;
+
+ dp[0] = list[0].s < list[0].e ? list[0].dl[list[0].s] : NULL;
+ dp[1] = list[1].s < list[1].e ? list[1].dl[list[1].s] : NULL;
+ if (!dp[0] && !dp[1])
+ break;
+ pos = !dp[0] ? 1 : (!dp[1] ? -1 : strcmp(dp[0], dp[1]));
+ k = pos > 0;
+ if (pos && !(option_mask32 & FLAG(N)))
+ printf("Only in %s: %s\n", p[k], dp[k]);
+ else {
+ char *fullpath[2], *path[2]; /* if -N */
+
+ for (int i = 0; i < 2; i++) {
+ if (pos == 0 || i == k) {
+ path[i] = fullpath[i] = concat_path_file(p[i], dp[i]);
+ stat(fullpath[i], &stb[i]);
+ } else {
+ fullpath[i] = concat_path_file(p[i], dp[1 - i]);
+ path[i] = (char *)bb_dev_null;
+ }
+ }
+ if (pos)
+ stat(fullpath[k], &stb[1 - k]);
+
+ if (S_ISDIR(stb[0].st_mode) && S_ISDIR(stb[1].st_mode))
+ printf("Common subdirectories: %s and %s\n", fullpath[0], fullpath[1]);
+ else if (!S_ISREG(stb[0].st_mode) && !S_ISDIR(stb[0].st_mode))
+ printf("File %s is not a regular file or directory and was skipped\n", fullpath[0]);
+ else if (!S_ISREG(stb[1].st_mode) && !S_ISDIR(stb[1].st_mode))
+ printf("File %s is not a regular file or directory and was skipped\n", fullpath[1]);
+ else if (S_ISDIR(stb[0].st_mode) != S_ISDIR(stb[1].st_mode)) {
+ if (S_ISDIR(stb[0].st_mode))
+ printf("File %s is a %s while file %s is a %s\n", fullpath[0], "directory", fullpath[1], "regular file");
+ else
+ printf("File %s is a %s while file %s is a %s\n", fullpath[0], "regular file", fullpath[1], "directory");
+ } else
+ print_status(diffreg(path), fullpath);
+
+ free(fullpath[0]);
+ free(fullpath[1]);
+ }
+ free(dp[k]);
+ list[k].s++;
if (pos == 0) {
- do_diff(p1, dp1, p2, dp2);
- dirlist1++;
- dirlist2++;
- } else if (pos < 0) {
- if (option_mask32 & FLAG_N)
- do_diff(p1, dp1, p2, NULL);
- else
- print_only(p1, dp1);
- dirlist1++;
- } else {
- if (option_mask32 & FLAG_N)
- do_diff(p1, NULL, p2, dp2);
- else
- print_only(p2, dp2);
- dirlist2++;
+ free(dp[1 - k]);
+ list[1 - k].s++;
}
}
+ if (ENABLE_FEATURE_CLEAN_UP) {
+ free(list[0].dl);
+ free(list[1].dl);
+ }
}
#endif
-
int diff_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int diff_main(int argc UNUSED_PARAM, char **argv)
{
int gotstdin = 0;
- char *f1, *f2;
+ char *file[2], *s_start = NULL;
llist_t *L_arg = NULL;
INIT_G();
@@ -1280,65 +874,49 @@ int diff_main(int argc UNUSED_PARAM, char **argv)
opt_complementary = "=2:L::U+";
getopt32(argv, "abdiL:NqrsS:tTU:wu"
"p" /* ignored (for compatibility) */,
- &L_arg, &opt_S_start, &opt_U_context);
- /*argc -= optind;*/
+ &L_arg, &s_start, &opt_U_context);
argv += optind;
while (L_arg) {
- if (label1 && label2)
+ if (label[0] && label[1])
bb_show_usage();
- if (label1) /* then label2 is NULL */
- label2 = label1;
- label1 = llist_pop(&L_arg);
+ if (label[0]) /* then label[1] is NULL */
+ label[1] = label[0];
+ label[0] = llist_pop(&L_arg);
}
-
- /*
- * Do sanity checks, fill in stb1 and stb2 and call the appropriate
- * driver routine. Both drivers use the contents of stb1 and stb2.
- */
- f1 = argv[0];
- f2 = argv[1];
- /* Compat: "diff file name_which_doesnt_exist" exits with 2 */
xfunc_error_retval = 2;
- if (LONE_DASH(f1)) {
- fstat(STDIN_FILENO, &stb1);
- gotstdin++;
- } else
- xstat(f1, &stb1);
- if (LONE_DASH(f2)) {
- fstat(STDIN_FILENO, &stb2);
- gotstdin++;
- } else
- xstat(f2, &stb2);
+ for (int i = 0; i < 2; i++) {
+ file[i] = argv[i];
+ /* Compat: "diff file name_which_doesnt_exist" exits with 2 */
+ if (LONE_DASH(file[i])) {
+ fstat(STDIN_FILENO, &stb[i]);
+ gotstdin++;
+ } else
+ xstat(file[i], &stb[i]);
+ }
xfunc_error_retval = 1;
-
- if (gotstdin && (S_ISDIR(stb1.st_mode) || S_ISDIR(stb2.st_mode)))
+ if (gotstdin && (S_ISDIR(stb[0].st_mode) || S_ISDIR(stb[1].st_mode)))
bb_error_msg_and_die("can't compare stdin to a directory");
- if (S_ISDIR(stb1.st_mode) && S_ISDIR(stb2.st_mode)) {
+ if (S_ISDIR(stb[0].st_mode) && S_ISDIR(stb[1].st_mode)) {
#if ENABLE_FEATURE_DIFF_DIR
- diffdir(f1, f2);
- return exit_status;
+ diffdir(file, s_start);
#else
bb_error_msg_and_die("no support for directory comparison");
#endif
- }
+ } else {
+ bool dirfile = S_ISDIR(stb[0].st_mode) || S_ISDIR(stb[1].st_mode);
+ bool dir = S_ISDIR(stb[1].st_mode);
+ if (dirfile) {
+ const char *slash = strrchr(file[!dir], '/');
+ file[dir] = concat_path_file(file[dir], slash ? slash + 1 : file[!dir]);
+ xstat(file[dir], &stb[dir]);
+ }
+ /* diffreg can get non-regular files here */
+ print_status(gotstdin > 1 ? STATUS_SAME : diffreg(file), file);
- if (S_ISDIR(stb1.st_mode)) { /* "diff dir file" */
- /* NB: "diff dir dir2/dir3/file" must become
- * "diff dir/file dir2/dir3/file" */
- char *slash = strrchr(f2, '/');
- f1 = concat_path_file(f1, slash ? slash + 1 : f2);
- xstat(f1, &stb1);
- }
- if (S_ISDIR(stb2.st_mode)) {
- char *slash = strrchr(f1, '/');
- f2 = concat_path_file(f2, slash ? slash + 1 : f1);
- xstat(f2, &stb2);
+ if (dirfile)
+ free(file[dir]);
}
- /* diffreg can get non-regular files here,
- * they are not both DIRestories */
- print_status((gotstdin > 1 ? D_SAME : diffreg(f1, f2, 0)),
- f1, f2 /*, NULL*/);
return exit_status;
}
diff --git a/testsuite/diff.tests b/testsuite/diff.tests
index 06bf163..f7bde2f 100755
--- a/testsuite/diff.tests
+++ b/testsuite/diff.tests
@@ -44,21 +44,18 @@ testing "diff of stdin, twice" \
"" \
"stdin"
-test x"$SKIP_KNOWN_BUGS" = x"" && \
testing "diff -b treats EOF as whitespace" \
'diff -ub - input; echo $?' \
"0\n" \
"abc" \
"abc "
-test x"$SKIP_KNOWN_BUGS" = x"" && \
testing "diff -b treats all spaces as equal" \
'diff -ub - input; echo $?' \
"0\n" \
"a \t c\n" \
"a\t \tc\n"
-test x"$SKIP_KNOWN_BUGS" = x"" && \
testing "diff always takes context from old file" \
"diff -ub - input | $TRIM_TAB" \
"\