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[PATCH 3/4] diff: introduce diff.<driver>.binary

From
Jeff King <peff@peff.net>
Date
Oct 5, 2008, 21:43 UTC
Message-ID
<20081005214336.GC21925@coredump.intra.peff.net>
In-Reply-To
<20081005214114.GA21875@coredump.intra.peff.net>

The "diff" gitattribute is somewhat overloaded right now. It can say one of three things:

  1. this file is definitely binary, or definitely not
     (i.e., diff or !diff)
  2. this file should use an external diff engine (i.e.,
     diff=foo, diff.foo.command = custom-script)
  3. this file should use particular funcname patterns
     (i.e., diff=foo, diff.foo.(x?)funcname = some-regex)

Most of the time, there is no conflict between these uses, since using one implies that the other is irrelevant (e.g., an external diff engine will decide for itself whether the file is binary).

However, there is at least one conflicting situation: there is no way to say "use the regular rules to determine whether this file is binary, but if we do diff it textually, use this funcname pattern." That is, currently setting diff=foo indicates that the file is definitely text.

This patch introduces a "binary" config option for a diff driver, so that one can explicitly set diff.foo.binary. We default this value to "don't know". That is, setting a diff attribute to "foo" and using "diff.foo.funcname" will have no effect on the binaryness of a file. To get the current behavior, one can set diff.foo.binary to true.

This patch also has one additional advantage: it cleans up the interface to the userdiff code a bit. Before, calling code had to know more about whether attributes were false, true, or unset to determine binaryness. Now that binaryness is a property of a driver, we can represent these situations just by passing back a driver struct.

Signed-off-by: Jeff King <peff@peff.net>
---
 diff.c     |   52 ++++++++++++++++++++++------------------------------
 diffcore.h |    8 ++++++--
 userdiff.c |   19 ++++++++++++++++---
 userdiff.h |    4 +---
 4 files changed, 45 insertions(+), 38 deletions(-)
diff --git a/diff.c b/diff.c
index 08f335f..ba4f6fa 100644
--- a/diff.c
+++ b/diff.c
@@ -1271,46 +1271,37 @@ static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two)
 	emit_binary_diff_body(file, two, one);
 }
 
-static void diff_filespec_check_attr(struct diff_filespec *one)
+void diff_filespec_load_driver(struct diff_filespec *one)
 {
-	struct userdiff_driver *drv;
-	int check_from_data = 0;
-
-	if (one->checked_attr)
-		return;
-
-	drv = userdiff_find_by_path(one->path);
-	one->is_binary = 0;
-
-	/* binaryness */
-	if (drv == USERDIFF_ATTR_TRUE)
-		;
-	else if (drv == USERDIFF_ATTR_FALSE)
-		one->is_binary = 1;
-	else
-		check_from_data = 1;
-
-	if (check_from_data) {
-		if (!one->data && DIFF_FILE_VALID(one))
-			diff_populate_filespec(one, 0);
-
-		if (one->data)
-			one->is_binary = buffer_is_binary(one->data, one->size);
-	}
+	if (!one->driver)
+		one->driver = userdiff_find_by_path(one->path);
+	if (!one->driver)
+		one->driver = userdiff_find_by_name("default");
 }
 
 int diff_filespec_is_binary(struct diff_filespec *one)
 {
-	diff_filespec_check_attr(one);
+	if (one->is_binary == -1) {
+		diff_filespec_load_driver(one);
+		if (one->driver->binary != -1)
+			one->is_binary = one->driver->binary;
+		else {
+			if (!one->data && DIFF_FILE_VALID(one))
+				diff_populate_filespec(one, 0);
+			if (one->data)
+				one->is_binary = buffer_is_binary(one->data,
+						one->size);
+			if (one->is_binary == -1)
+				one->is_binary = 0;
+		}
+	}
 	return one->is_binary;
 }
 
 static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
 {
-	struct userdiff_driver *drv = userdiff_find_by_path(one->path);
-	if (!drv)
-		drv = userdiff_find_by_name("default");
-	return drv && drv->funcname.pattern ? &drv->funcname : NULL;
+	diff_filespec_load_driver(one);
+	return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
 }
 
 void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
@@ -1558,6 +1549,7 @@ struct diff_filespec *alloc_filespec(const char *path)
 	spec->path = (char *)(spec + 1);
 	memcpy(spec->path, path, namelen+1);
 	spec->count = 1;
+	spec->is_binary = -1;
 	return spec;
 }
 
diff --git a/diffcore.h b/diffcore.h
index 8ae3578..713cca7 100644
--- a/diffcore.h
+++ b/diffcore.h
@@ -22,6 +22,8 @@
 
 #define MINIMUM_BREAK_SIZE     400 /* do not break a file smaller than this */
 
+struct userdiff_driver;
+
 struct diff_filespec {
 	unsigned char sha1[20];
 	char *path;
@@ -40,8 +42,10 @@ struct diff_filespec {
 #define DIFF_FILE_VALID(spec) (((spec)->mode) != 0)
 	unsigned should_free : 1; /* data should be free()'ed */
 	unsigned should_munmap : 1; /* data should be munmap()'ed */
-	unsigned checked_attr : 1;
-	unsigned is_binary : 1; /* data should be considered "binary" */
+
+	struct userdiff_driver *driver;
+	/* data should be considered "binary"; -1 means "don't know yet" */
+	int is_binary;
 };
 
 extern struct diff_filespec *alloc_filespec(const char *);
diff --git a/userdiff.c b/userdiff.c
index 3406adc..ac6d4a1 100644
--- a/userdiff.c
+++ b/userdiff.c
@@ -7,7 +7,7 @@ static int ndrivers;
 static int drivers_alloc;
 
 #define FUNCNAME(name, pattern) \
-	{ name, NULL, { pattern, REG_EXTENDED } }
+	{ name, NULL, -1, { pattern, REG_EXTENDED } }
 static struct userdiff_driver builtin_drivers[] = {
 FUNCNAME("html", "^[ \t]*(<[Hh][1-6][ \t].*>.*)$"),
 FUNCNAME("java",
@@ -23,22 +23,23 @@ FUNCNAME("python", "^[ \t]*((class|def)[ \t].*)$"),
 FUNCNAME("ruby", "^[ \t]*((class|module|def)[ \t].*)$"),
 FUNCNAME("bibtex", "(@[a-zA-Z]{1,}[ \t]*\\{{0,1}[ \t]*[^ \t\"@',\\#}{~%]*).*$"),
 FUNCNAME("tex", "^(\\\\((sub)*section|chapter|part)\\*{0,1}\\{.*)$"),
+{ "default", NULL, -1, { NULL, 0 } },
 };
 #undef FUNCNAME
 
 static struct userdiff_driver driver_true = {
 	"diff=true",
 	NULL,
+	0,
 	{ NULL, 0 }
 };
-struct userdiff_driver *USERDIFF_ATTR_TRUE = &driver_true;
 
 static struct userdiff_driver driver_false = {
 	"!diff",
 	NULL,
+	1,
 	{ NULL, 0 }
 };
-struct userdiff_driver *USERDIFF_ATTR_FALSE = &driver_false;
 
 static struct userdiff_driver *userdiff_find_by_namelen(const char *k, int len)
 {
@@ -80,6 +81,7 @@ static struct userdiff_driver *parse_driver(const char *var,
 		drv = &drivers[ndrivers++];
 		memset(drv, 0, sizeof(*drv));
 		drv->name = xmemdupz(name, namelen);
+		drv->binary = -1;
 	}
 	return drv;
 }
@@ -100,6 +102,15 @@ static int parse_string(const char **d, const char *k, const char *v)
 	return 1;
 }
 
+static int parse_tristate(int *b, const char *k, const char *v)
+{
+	if (v && !strcasecmp(v, "auto"))
+		*b = -1;
+	else
+		*b = git_config_bool(k, v);
+	return 1;
+}
+
 int userdiff_config_basic(const char *k, const char *v)
 {
 	struct userdiff_driver *drv;
@@ -108,6 +119,8 @@ int userdiff_config_basic(const char *k, const char *v)
 		return parse_funcname(&drv->funcname, k, v, 0);
 	if ((drv = parse_driver(k, v, "xfuncname")))
 		return parse_funcname(&drv->funcname, k, v, REG_EXTENDED);
+	if ((drv = parse_driver(k, v, "binary")))
+		return parse_tristate(&drv->binary, k, v);
 
 	return 0;
 }
diff --git a/userdiff.h b/userdiff.h
index c64c5f5..1c1eb04 100644
--- a/userdiff.h
+++ b/userdiff.h
@@ -9,12 +9,10 @@ struct userdiff_funcname {
 struct userdiff_driver {
 	const char *name;
 	const char *external;
+	int binary;
 	struct userdiff_funcname funcname;
 };
 
-extern struct userdiff_driver *USERDIFF_ATTR_TRUE;
-extern struct userdiff_driver *USERDIFF_ATTR_FALSE;
-
 int userdiff_config_basic(const char *k, const char *v);
 int userdiff_config_porcelain(const char *k, const char *v);
 struct userdiff_driver *userdiff_find_by_name(const char *name);

-- 
1.6.0.2.639.g4d7f.dirty
Previous: Jeff KingNext: Johannes Sixt
Message 20 of 85 in “Implementation of a "textconv" filter for easy custom diff.”
  1. Matthieu MoySep 28, 2008
  2. Facility to have multiple kinds of drivers for diff.Matthieu Moy, Sep 28, 2008
  3. Implement run_command_to_buf (spawn a process and reads its stdout)Matthieu Moy, Sep 28, 2008
  4. Implement a textconv filter for "git diff"Matthieu Moy, Sep 28, 2008
  5. Document the textconv filter.Matthieu Moy, Sep 28, 2008
  6. Add a basic test for the textconv filter.Matthieu Moy, Sep 28, 2008
  7. Johannes SixtSep 28, 2008
  8. Matthieu MoySep 28, 2008
  9. Jeff KingSep 28, 2008
  10. Matthieu MoySep 28, 2008
  11. Jeff KingSep 28, 2008
  12. Jeff KingSep 28, 2008
  13. Matthieu MoySep 28, 2008
  14. Jeff KingSep 28, 2008
  15. Matthieu MoySep 30, 2008
  16. Jeff KingSep 30, 2008
  17. 0/4 diff text conversion filterJeff King, Oct 5, 2008
  18. 1/4 t4012: use test_cmp instead of cmpJeff King, Oct 5, 2008
  19. 2/4 diff: unify external diff and funcname parsing codeJeff King, Oct 5, 2008
  20. 3/4 diff: introduce diff.<driver>.binaryJeff King, Oct 5, 2008
  21. Johannes SixtOct 7, 2008
  22. Jeff KingOct 7, 2008
  23. Johannes SixtOct 7, 2008
  24. Junio C HamanoOct 12, 2008
  25. Jeff KingOct 13, 2008
  26. Junio C HamanoOct 13, 2008
  27. Jeff KingOct 13, 2008
  28. Johannes SixtOct 13, 2008
  29. Junio C HamanoOct 13, 2008
  30. Matthieu MoyOct 13, 2008
  31. Jeff KingOct 24, 2008
  32. 1/5 diff: add missing static declarationJeff King, Oct 24, 2008
  33. 2/5 add userdiff textconv testsJeff King, Oct 24, 2008
  34. 3/5 refactor userdiff textconv codeJeff King, Oct 24, 2008
  35. Johannes SixtOct 24, 2008
  36. Jeff KingOct 24, 2008
  37. Jeff KingOct 24, 2008
  38. Johannes SixtOct 24, 2008
  39. Jeff KingOct 24, 2008
  40. Junio C HamanoOct 24, 2008
  41. Jeff KingOct 24, 2008
  42. Jeff KingOct 24, 2008
  43. Jeff KingOct 25, 2008
  44. 1/7 diff: add missing static declarationJeff King, Oct 25, 2008
  45. 2/7 add userdiff textconv testsJeff King, Oct 25, 2008
  46. 3/7 textconv: assume text-converted contents are not binaryJeff King, Oct 25, 2008
  47. 4/7 textconv: don't convert for every operationJeff King, Oct 25, 2008
  48. Junio C HamanoOct 25, 2008
  49. Jeff KingOct 25, 2008
  50. Junio C HamanoOct 25, 2008
  51. Jeff KingOct 25, 2008
  52. Junio C HamanoOct 25, 2008
  53. Junio C HamanoOct 25, 2008
  54. Jeff KingOct 26, 2008
  55. Jeff KingOct 26, 2008
  56. 1/8 diff: add missing static declarationJeff King, Oct 26, 2008
  57. 2/8 document the diff driver textconv featureJeff King, Oct 26, 2008
  58. 3/8 add userdiff textconv testsJeff King, Oct 26, 2008
  59. 4/8 refactor userdiff textconv codeJeff King, Oct 26, 2008
  60. 5/8 userdiff: require explicitly allowing textconvJeff King, Oct 26, 2008
  61. 6/8 only textconv regular filesJeff King, Oct 26, 2008
  62. 7/8 wt-status: load diff ui configJeff King, Oct 26, 2008
  63. Junio C HamanoOct 27, 2008
  64. Jeff KingOct 27, 2008
  65. 8/8 enable textconv for diff in verbose status/commitJeff King, Oct 26, 2008
  66. 5/7 userdiff: require explicitly allowing textconvJeff King, Oct 25, 2008
  67. 6/7 document the diff driver textconv featureJeff King, Oct 25, 2008
  68. 7/7 only textconv regular filesJeff King, Oct 25, 2008
  69. 4/5 userdiff: require explicitly allowing textconvJeff King, Oct 24, 2008
  70. Johannes SixtOct 24, 2008
  71. 5/5 document the diff driver textconv featureJeff King, Oct 24, 2008
  72. Johannes SixtOct 24, 2008
  73. 4/4 diff: add filter for converting binary to textJeff King, Oct 5, 2008
  74. Jakub NarebskiOct 5, 2008
  75. Johannes SixtOct 6, 2008
  76. Jeff KingOct 6, 2008
  77. Johannes SixtOct 6, 2008
  78. Matthieu MoyOct 6, 2008
  79. Jeff KingOct 7, 2008
  80. Johannes SixtOct 7, 2008
  81. Jeff KingOct 7, 2008
  82. Matthieu MoyOct 7, 2008
  83. Jeff KingOct 7, 2008
  84. Johannes SixtOct 7, 2008
  85. Jeff KingOct 13, 2008

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