Changeset 4151 for zzuf/trunk/srcTweet

Timestamp:

Dec 20, 2009, 1:24:50 PM (10 years ago)

Author:

Sam Hocevar

Message:

Buffer debug output to reduce the number of write() calls and allow to
output information that was logged before the library was initialised.

File:

• zzuf/trunk/src/libzzuf/debug.c (modified) (14 diffs)

zzuf/trunk/src/libzzuf/debug.c

@@ -25 +25 @@
 #endif
 #include <stdio.h>
+#include <string.h>
 #if defined HAVE_UNISTD_H
 #   include <unistd.h>
@@ -43 +44 @@
  * either in base 10 or in hexadecimal.
  */
-#define WRITE_INT(fd, i, base) \
+#define WRITE_INT(i, base) \
     do \
     { \
         char buf[128], *b = buf + 127; \
         if(i <= 0) \
-            write(fd, (i = -i) ? "-" : "0", 1); /* XXX: hack here */ \
+            append((i = -i) ? "-" : "0", 1); /* XXX: hack here */ \
         while(i) \
         { \
@@ -54 +55 @@
             i /= base; \
         } \
-        write(fd, b + 1, (int)(buf + 127 - b)); \
+        append(b + 1, (int)(buf + 127 - b)); \
     } while(0)
+
+/* Temporary buffer for deferred output */
+char debugbuffer[BUFSIZ];
+size_t debugcount = 1;
 
 void _zz_debug(char const *format, ...)
@@ -86 +91 @@
  *  - fprintf(stderr, "\n");
  */
+static inline void append(void const *data, size_t count)
+{
+    if (debugcount + count <= sizeof(debugbuffer))
+    {
+        memcpy(debugbuffer + debugcount, data, count);
+        debugcount += count;
+    }
+}
+
 static void mydebug(char const *format, va_list args)
 {
@@ -92 +106 @@
     int saved_errno;
 
-    if(_zz_debugfd < 0)
-        return;
-
     saved_errno = errno;
 
-    write(_zz_debugfd, "** zzuf debug ** ", 17);
+    /* If there is spare data and the debug fd is open, we send the data */
+    if (debugcount && _zz_debugfd >= 0)
+    {
+        write(_zz_debugfd, debugbuffer, debugcount);
+        debugcount = 0;
+    }
+
+    append("** zzuf debug ** ", 17);
     for(f = format; *f; f++)
     {
         if(*f != '%')
         {
-            write(_zz_debugfd, f, 1);
+            append(f, 1);
             continue;
         }
@@ -114 +132 @@
             char i = (char)(unsigned char)va_arg(args, int);
             if(i >= 0x20 && i < 0x7f)
-                write(_zz_debugfd, &i, 1);
+                append(&i, 1);
             else if(i == '\n')
-                write(_zz_debugfd, "\\n", 2);
+                append("\\n", 2);
             else if(i == '\t')
-                write(_zz_debugfd, "\\t", 2);
+                append("\\t", 2);
             else if(i == '\r')
-                write(_zz_debugfd, "\\r", 2);
+                append("\\r", 2);
             else
             {
-                write(_zz_debugfd, "\\x", 2);
-                write(_zz_debugfd, hex2char + ((i & 0xf0) >> 4), 1);
-                write(_zz_debugfd, hex2char + (i & 0x0f), 1);
+                append("\\x", 2);
+                append(hex2char + ((i & 0xf0) >> 4), 1);
+                append(hex2char + (i & 0x0f), 1);
             }
         }
@@ -131 +149 @@
         {
             int i = va_arg(args, int);
-            WRITE_INT(_zz_debugfd, i, 10);
+            WRITE_INT(i, 10);
         }
         else if(*f == 'x')
         {
             int i = va_arg(args, int);
-            WRITE_INT(_zz_debugfd, i, 16);
+            WRITE_INT(i, 16);
         }
         else if(f[0] == 'l' && (f[1] == 'i' || f[1] == 'd'))
         {
             long int i = va_arg(args, long int);
-            WRITE_INT(_zz_debugfd, i, 10);
+            WRITE_INT(i, 10);
             f++;
         }
@@ -147 +165 @@
         {
             long long int i = va_arg(args, long long int);
-            WRITE_INT(_zz_debugfd, i, 10);
+            WRITE_INT(i, 10);
             f += 2;
         }
@@ -154 +172 @@
             double g = va_arg(args, double), h = 0.0000001;
             int i = (int)g;
-            WRITE_INT(_zz_debugfd, i, 10);
+            WRITE_INT(i, 10);
             for(i = 0; i < 7; i++)
             {
@@ -162 +180 @@
                     break;
                 if(i == 0)
-                    write(_zz_debugfd, ".", 1);
-                write(_zz_debugfd, hex2char + (int)g, 1);
+                    append(".", 1);
+                append(hex2char + (int)g, 1);
             }
         }
@@ -170 +188 @@
             uintptr_t i = va_arg(args, uintptr_t);
             if(!i)
-                write(_zz_debugfd, "NULL", 5);
+                append("NULL", 5);
             else
             {
-                write(_zz_debugfd, "0x", 2);
-                WRITE_INT(_zz_debugfd, i, 16);
+                append("0x", 2);
+                WRITE_INT(i, 16);
             }
         }
@@ -181 +199 @@
             char *s = va_arg(args, char *);
             if(!s)
-                write(_zz_debugfd, "(nil)", 5);
+                append("(nil)", 5);
             else
             {
@@ -187 +205 @@
                 while(s[l])
                     l++;
-                write(_zz_debugfd, s, l);
+                append(s, l);
             }
         }
@@ -193 +211 @@
         {
             int i = va_arg(args, int);
-            write(_zz_debugfd, hex2char + ((i & 0xf0) >> 4), 1);
-            write(_zz_debugfd, hex2char + (i & 0x0f), 1);
+            append(hex2char + ((i & 0xf0) >> 4), 1);
+            append(hex2char + (i & 0x0f), 1);
             f += 2;
         }
         else
         {
-            write(_zz_debugfd, f - 1, 2);
-        }
-    }
-    write(_zz_debugfd, "\n", 1);
+            append(f - 1, 2);
+        }
+    }
+    append("\n", 1);
+
+    /* If the debug fd is open, we send the data */
+    if (_zz_debugfd >= 0)
+    {
+        write(_zz_debugfd, debugbuffer, debugcount);
+        debugcount = 0;
+    }
+
     errno = saved_errno;
 }
+