Fossil SCM

Faster determination of binary files, by not only checking for NUL <p>re-use looks_like_blob

jan.nijtmans 2012-10-30 20:10 UTC trunk
Commit 0ba08f9d26ecb3a53d79d05d3f95dfc8cc36c248
Parent bdbe6c74b82231e…
2 files changed +12 -6 +1 -12
~ src/diff.c ~ src/doc.c
M src/diff.c
+12 -6
--- src/diff.c
+++ src/diff.c
@@ -189,31 +189,37 @@
189189
 **
190190
 ** (-2) -- The content appears to consist entirely of text, in the
191191
 ** UTF-16 (BE or LE) encoding.
192192
 */
193193
 int looks_like_text(const Blob *pContent){
194
- const char *z = blob_buffer(pContent);
194
+ const unsigned char *z = blob_buffer(pContent);
195195
 unsigned int n = blob_size(pContent);
196
- int j, c;
196
+ int j;
197
+ unsigned char c;
197198
 int result = 1; /* Assume text with no CR/NL */
199
+ static const char isBinary[256] = {
200
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1,
201
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1
202
+ };
203
+
198204
199205
 /* Check individual lines.
200206
 */
201207
 if( n==0 ) return result; /* Empty file -> text */
202208
 c = *z;
203
- if( c==0 ) return 0; /* \000 byte in a file -> binary */
209
+ if( isBinary[c] ) return 0; /* non-text byte in a file -> binary */
204210
 if ( n > 1 ){
205
- if ( (c==(char)0xff) && (z[1]==(char)0xfe) ){
211
+ if ( (c==0xff) && (z[1]==0xfe) ){
206212
 return -2;
207
- } else if ( (c==(char)0xfe) && (z[1]==(char)0xff) ){
213
+ } else if ( (c==0xfe) && (z[1]==0xff) ){
208214
 return -2;
209215
 }
210216
 }
211217
 j = (c!='\n');
212218
 while( --n>0 ){
213219
 c = *++z; ++j;
214
- if( c==0 ) return 0; /* \000 byte in a file -> binary */
220
+ if( isBinary[c] ) return 0; /* \000 byte in a file -> binary */
215221
 if( c=='\n' ){
216222
 if( z[-1]=='\r' ){
217223
 result = -1; /* Contains CR/NL, continue */
218224
 }
219225
 if( j>LENGTH_MASK ){
220226
--- src/diff.c
+++ src/diff.c
@@ -189,31 +189,37 @@
189 **
190 ** (-2) -- The content appears to consist entirely of text, in the
191 ** UTF-16 (BE or LE) encoding.
192 */
193 int looks_like_text(const Blob *pContent){
194 const char *z = blob_buffer(pContent);
195 unsigned int n = blob_size(pContent);
196 int j, c;
 
197 int result = 1; /* Assume text with no CR/NL */
 
 
 
 
 
198
199 /* Check individual lines.
200 */
201 if( n==0 ) return result; /* Empty file -> text */
202 c = *z;
203 if( c==0 ) return 0; /* \000 byte in a file -> binary */
204 if ( n > 1 ){
205 if ( (c==(char)0xff) && (z[1]==(char)0xfe) ){
206 return -2;
207 } else if ( (c==(char)0xfe) && (z[1]==(char)0xff) ){
208 return -2;
209 }
210 }
211 j = (c!='\n');
212 while( --n>0 ){
213 c = *++z; ++j;
214 if( c==0 ) return 0; /* \000 byte in a file -> binary */
215 if( c=='\n' ){
216 if( z[-1]=='\r' ){
217 result = -1; /* Contains CR/NL, continue */
218 }
219 if( j>LENGTH_MASK ){
220
--- src/diff.c
+++ src/diff.c
@@ -189,31 +189,37 @@
189 **
190 ** (-2) -- The content appears to consist entirely of text, in the
191 ** UTF-16 (BE or LE) encoding.
192 */
193 int looks_like_text(const Blob *pContent){
194 const unsigned char *z = blob_buffer(pContent);
195 unsigned int n = blob_size(pContent);
196 int j;
197 unsigned char c;
198 int result = 1; /* Assume text with no CR/NL */
199 static const char isBinary[256] = {
200 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1,
201 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1
202 };
203
204
205 /* Check individual lines.
206 */
207 if( n==0 ) return result; /* Empty file -> text */
208 c = *z;
209 if( isBinary[c] ) return 0; /* non-text byte in a file -> binary */
210 if ( n > 1 ){
211 if ( (c==0xff) && (z[1]==0xfe) ){
212 return -2;
213 } else if ( (c==0xfe) && (z[1]==0xff) ){
214 return -2;
215 }
216 }
217 j = (c!='\n');
218 while( --n>0 ){
219 c = *++z; ++j;
220 if( isBinary[c] ) return 0; /* \000 byte in a file -> binary */
221 if( c=='\n' ){
222 if( z[-1]=='\r' ){
223 result = -1; /* Contains CR/NL, continue */
224 }
225 if( j>LENGTH_MASK ){
226
M src/doc.c
+1 -12
--- src/doc.c
+++ src/doc.c
@@ -35,15 +35,10 @@
3535
 const char *mimetype_from_content(Blob *pBlob){
3636
 int i;
3737
 int n;
3838
 const unsigned char *x;
3939
40
- static const char isBinary[] = {
41
- 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 0, 0, 1, 1,
42
- 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1,
43
- };
44
-
4540
 /* A table of mimetypes based on file content prefixes
4641
 */
4742
 static const struct {
4843
 const char *zPrefix; /* The file prefix */
4944
 int size; /* Length of the prefix */
@@ -56,17 +51,11 @@
5651
 { "\377\330\377", 3, "image/jpeg" },
5752
 };
5853
5954
 x = (const unsigned char*)blob_buffer(pBlob);
6055
 n = blob_size(pBlob);
61
- for(i=0; i<n; i++){
62
- unsigned char c = x[i];
63
- if( c<=0x1f && isBinary[c] ){
64
- break;
65
- }
66
- }
67
- if( i>=n ){
56
+ if( looks_like_text(pBlob) ){
6857
 return 0; /* Plain text */
6958
 }
7059
 for(i=0; i<sizeof(aMime)/sizeof(aMime[0]); i++){
7160
 if( n>=aMime[i].size && memcmp(x, aMime[i].zPrefix, aMime[i].size)==0 ){
7261
 return aMime[i].zMimetype;
7362
--- src/doc.c
+++ src/doc.c
@@ -35,15 +35,10 @@
35 const char *mimetype_from_content(Blob *pBlob){
36 int i;
37 int n;
38 const unsigned char *x;
39
40 static const char isBinary[] = {
41 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 0, 0, 1, 1,
42 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1,
43 };
44
45 /* A table of mimetypes based on file content prefixes
46 */
47 static const struct {
48 const char *zPrefix; /* The file prefix */
49 int size; /* Length of the prefix */
@@ -56,17 +51,11 @@
56 { "\377\330\377", 3, "image/jpeg" },
57 };
58
59 x = (const unsigned char*)blob_buffer(pBlob);
60 n = blob_size(pBlob);
61 for(i=0; i<n; i++){
62 unsigned char c = x[i];
63 if( c<=0x1f && isBinary[c] ){
64 break;
65 }
66 }
67 if( i>=n ){
68 return 0; /* Plain text */
69 }
70 for(i=0; i<sizeof(aMime)/sizeof(aMime[0]); i++){
71 if( n>=aMime[i].size && memcmp(x, aMime[i].zPrefix, aMime[i].size)==0 ){
72 return aMime[i].zMimetype;
73
--- src/doc.c
+++ src/doc.c
@@ -35,15 +35,10 @@
35 const char *mimetype_from_content(Blob *pBlob){
36 int i;
37 int n;
38 const unsigned char *x;
39
 
 
 
 
 
40 /* A table of mimetypes based on file content prefixes
41 */
42 static const struct {
43 const char *zPrefix; /* The file prefix */
44 int size; /* Length of the prefix */
@@ -56,17 +51,11 @@
51 { "\377\330\377", 3, "image/jpeg" },
52 };
53
54 x = (const unsigned char*)blob_buffer(pBlob);
55 n = blob_size(pBlob);
56 if( looks_like_text(pBlob) ){
 
 
 
 
 
 
57 return 0; /* Plain text */
58 }
59 for(i=0; i<sizeof(aMime)/sizeof(aMime[0]); i++){
60 if( n>=aMime[i].size && memcmp(x, aMime[i].zPrefix, aMime[i].size)==0 ){
61 return aMime[i].zMimetype;
62

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