libc: add encode(2) variants for custom alphabets

[plan9front.git] / sys / src / libc / port / u32.c

diff --git a/sys/src/libc/port/u32.c b/sys/src/libc/port/u32.c
index 9ad9eb781ccdea952e9bce678579a92ccc0b7dbd..a7abdc012a70ecb8e9bab1a1e18a9ec1d63d955f 100644 (file)
--- a/sys/src/libc/port/u32.c
+++ b/sys/src/libc/port/u32.c
@@ -25,7 +25,7 @@ dec32chr(int c)
 }
 
 int
-dec32(uchar *dest, int ndest, char *src, int nsrc)
+dec32x(uchar *dest, int ndest, char *src, int nsrc, int (*chr)(int))
 {
        uchar *start;
        int i, j, u[8];
@@ -35,7 +35,7 @@ dec32(uchar *dest, int ndest, char *src, int nsrc)
        start = dest;
        while(nsrc>=8){
                for(i=0; i<8; i++){
-                       j = dec32chr(src[i]);
+                       j = chr(src[i]);
                        if(j < 0)
                                j = 0;
                        u[i] = j;
@@ -52,7 +52,7 @@ dec32(uchar *dest, int ndest, char *src, int nsrc)
                if(nsrc == 1 || nsrc == 3 || nsrc == 6)
                        return -1;
                for(i=0; i<nsrc; i++){
-                       j = dec32chr(src[i]);
+                       j = chr(src[i]);
                        if(j < 0)
                                j = 0;
                        u[i] = j;
@@ -73,7 +73,7 @@ out:
 }
 
 int
-enc32(char *dest, int ndest, uchar *src, int nsrc)
+enc32x(char *dest, int ndest, uchar *src, int nsrc, int (*chr)(int))
 {
        char *start;
        int j;
@@ -83,50 +83,62 @@ enc32(char *dest, int ndest, uchar *src, int nsrc)
        start = dest;
        while(nsrc>=5){
                j = (0x1f & (src[0]>>3));
-               *dest++ = enc32chr(j);
+               *dest++ = chr(j);
                j = (0x1c & (src[0]<<2)) | (0x03 & (src[1]>>6));
-               *dest++ = enc32chr(j);
+               *dest++ = chr(j);
                j = (0x1f & (src[1]>>1));
-               *dest++ = enc32chr(j);
+               *dest++ = chr(j);
                j = (0x10 & (src[1]<<4)) | (0x0f & (src[2]>>4));
-               *dest++ = enc32chr(j);
+               *dest++ = chr(j);
                j = (0x1e & (src[2]<<1)) | (0x01 & (src[3]>>7));
-               *dest++ = enc32chr(j);
+               *dest++ = chr(j);
                j = (0x1f & (src[3]>>2));
-               *dest++ = enc32chr(j);
+               *dest++ = chr(j);
                j = (0x18 & (src[3]<<3)) | (0x07 & (src[4]>>5));
-               *dest++ = enc32chr(j);
+               *dest++ = chr(j);
                j = (0x1f & (src[4]));
-               *dest++ = enc32chr(j);
+               *dest++ = chr(j);
                src  += 5;
                nsrc -= 5;
        }
        if(nsrc){
                j = (0x1f & (src[0]>>3));
-               *dest++ = enc32chr(j);
+               *dest++ = chr(j);
                j = (0x1c & (src[0]<<2));
                if(nsrc == 1)
                        goto out;
                j |= (0x03 & (src[1]>>6));
-               *dest++ = enc32chr(j);
+               *dest++ = chr(j);
                j = (0x1f & (src[1]>>1));
-               *dest++ = enc32chr(j);
+               *dest++ = chr(j);
                j = (0x10 & (src[1]<<4));
                if(nsrc == 2)
                        goto out;
                j |= (0x0f & (src[2]>>4));
-               *dest++ = enc32chr(j);
+               *dest++ = chr(j);
                j = (0x1e & (src[2]<<1));
                if(nsrc == 3)
                        goto out;
                j |= (0x01 & (src[3]>>7));
-               *dest++ = enc32chr(j);
+               *dest++ = chr(j);
                j = (0x1f & (src[3]>>2));
-               *dest++ = enc32chr(j);
+               *dest++ = chr(j);
                j = (0x18 & (src[3]<<3));
 out:
-               *dest++ = enc32chr(j);
+               *dest++ = chr(j);
        }
        *dest = 0;
        return dest-start;
 }
+
+int
+enc32(char *dest, int ndest, uchar *src, int nsrc)
+{
+       return enc32x(dest, ndest, src, nsrc, enc32chr);
+}
+
+int
+dec32(uchar *dest, int ndest, char *src, int nsrc)
+{
+       return dec32x(dest, ndest, src, nsrc, dec32chr);
+}