increase readability of encode.{c,h}

encode.c

@@ -33,75 +33,76 @@ unsigned char asciitob64[] = {
 
 
 int
-encode(unsigned char *op, int olen, unsigned char *sp, int url)
+encode(unsigned char *octbuf, int octbufsize, unsigned char *sxtbuf, int urlencoded)
 {
-    int tmp;
     unsigned char *table;
-    unsigned char *sbeg;
-    unsigned char *tend;
+    unsigned char *sxtbegin;
+    unsigned char *octleft;
+    int highorderbits;
 
-    table = (!url) ? b64toascii : b64urltoascii;
+    table = (!urlencoded) ? b64toascii : b64urltoascii;
 
-    sbeg = sp;
-    tend = op + olen - (olen % 3);
-    while (op < tend) {
-        *sp++ = table[(*op & ~3) >> 2];
-        tmp = (*op++ & 3) << 4;
-        *sp++ = table[tmp + ((*op & ~15) >> 4)];
-        tmp = (*op++ & 15) << 2;
-        *sp++ = table[tmp + ((*op & 192) >> 6)];
-        *sp++ = table[*op++ & ~192];
+    sxtbegin = sxtbuf;
+    octleft = octbuf + octbufsize - (octbufsize % 3);
+    while (octbuf < octleft) {
+        *sxtbuf++ = table[(*octbuf & ~3) >> 2];
+        highorderbits = (*octbuf++ & 3) << 4;
+        *sxtbuf++ = table[highorderbits + ((*octbuf & ~15) >> 4)];
+        highorderbits = (*octbuf++ & 15) << 2;
+        *sxtbuf++ = table[highorderbits + ((*octbuf & 192) >> 6)];
+        *sxtbuf++ = table[*octbuf++ & ~192];
     }
-    switch (olen % 3) {
+    switch (octbufsize % 3) {
         case 2:
-            *sp++ = table[(*op & ~3) >> 2];
-            tmp = (*op++ & 3) << 4;
-            *sp++ = table[tmp + ((*op & ~15) >> 4)];
-            *sp++ = table[(*op & 15) << 2];
-            *sp++ = PADDING;
+            *sxtbuf++ = table[(*octbuf & ~3) >> 2];
+            highorderbits = (*octbuf++ & 3) << 4;
+            *sxtbuf++ = table[highorderbits + ((*octbuf & ~15) >> 4)];
+            *sxtbuf++ = table[(*octbuf & 15) << 2];
+            *sxtbuf++ = PADDING;
             break;
         case 1:
-            *sp++ = table[(*op & ~3) >> 2];
-            *sp++ = table[(*op & 3) << 4];
-            *sp++ = PADDING;
-            *sp++ = PADDING;
+            *sxtbuf++ = table[(*octbuf & ~3) >> 2];
+            *sxtbuf++ = table[(*octbuf & 3) << 4];
+            *sxtbuf++ = PADDING;
+            *sxtbuf++ = PADDING;
             break;
     }
 
-    return sp-sbeg;
+    return sxtbuf-sxtbegin;
 }
 
 int
-decode(unsigned char *sp, int slen, unsigned char *op)
+decode(unsigned char *sxtbuf, int sxtbufsize, unsigned char *octbuf)
 {
-    int tmp, b;
-    unsigned char *obeg;
-    unsigned char *qend;
+    unsigned char *octbegin;
+    unsigned char *sxtleft;
+    int highorderbits;
+    int loworderbits;
 
-    obeg = op;
-    qend = sp + slen - (slen % 4);
-    while (sp < qend) {
-        tmp = asciitob64[*sp++] << 2;
-        b = asciitob64[*sp++];
-        *op++ = tmp + ((b & ~15) >> 4);
-        tmp = (b & 15) << 4;
-        b = asciitob64[*sp++];
-        *op++ = tmp + ((b & ~3) >> 2);
-        *op++ = ((b & 3) << 6) + asciitob64[*sp++];
+    octbegin = octbuf;
+    sxtleft = sxtbuf + sxtbufsize - (sxtbufsize % 4);
+    while (sxtbuf < sxtleft) {
+        highorderbits = asciitob64[*sxtbuf++] << 2;
+        loworderbits = asciitob64[*sxtbuf++];
+        *octbuf++ = highorderbits + ((loworderbits & ~15) >> 4);
+        highorderbits = (loworderbits & 15) << 4;
+        loworderbits = asciitob64[*sxtbuf++];
+        *octbuf++ = highorderbits + ((loworderbits & ~3) >> 2);
+        *octbuf++ = ((loworderbits & 3) << 6) + asciitob64[*sxtbuf++];
     }
-    switch (slen % 4) {
+    switch (sxtbufsize % 4) {
         case 3:
-            tmp = asciitob64[*sp++] << 2;
-            b = asciitob64[*sp++];
-            *op++ = tmp + ((b & ~15) >> 4);
-            tmp = (b & 15) << 4;
-            *op++ = tmp + ((asciitob64[*sp++] & ~3) >> 2);
+            highorderbits = asciitob64[*sxtbuf++] << 2;
+            loworderbits = asciitob64[*sxtbuf++];
+            *octbuf++ = highorderbits + ((loworderbits & ~15) >> 4);
+            highorderbits = (loworderbits & 15) << 4;
+            *octbuf++ = highorderbits + ((asciitob64[*sxtbuf++] & ~3) >> 2);
             break;
         case 2:
-            tmp = asciitob64[*sp++] << 2;
-            *op++ = tmp + ((asciitob64[*sp++] & ~15) >> 4);
+            highorderbits = asciitob64[*sxtbuf++] << 2;
+            *octbuf++ = highorderbits + ((asciitob64[*sxtbuf++] & ~15) >> 4);
             break;
     }
 
-    return op-obeg;
+    return octbuf-octbegin;
 }

encode.h

@@ -2,9 +2,9 @@
 #define ENCODE_H
 
 int
-encode(unsigned char *op, int olen, unsigned char *sp, int url);
+encode(unsigned char *octbuf, int octbufsize, unsigned char *sxtbuf, int urlencoded);
 
 int
-decode(unsigned char *sp, int slen, unsigned char *op);
+decode(unsigned char *sxtbuf, int sxtbufsize, unsigned char *octbuf);
 
 #endif

input.c

@@ -3,27 +3,30 @@
 #define PADDING  '='
 
 int
-readb(FILE *fp, unsigned char *s, int slen)
+readb(FILE *fptr, unsigned char *buf, int bufsize)
 {
-    int read, tread;
-    unsigned char *send, *sbeg;
-    unsigned char *l, *r;
+    int read;
+    int total;
+    unsigned char *begin;
+    unsigned char *end;
+    unsigned char *left;
+    unsigned char *right;
     
-    read = tread = 0;
-    sbeg = l = r = s;
-    while (tread < slen && (read = fread(l, sizeof(*l), slen-tread, fp))) {
-        tread += read;
-        send = s + tread;
-        for (r = l; r < send; ++r)
-            if (*r != '\n')
-                *l++ = *r;
-        tread -= r - l;
-        if (l > sbeg) {
-            for (--l; *l == PADDING; --l)
-                ;
-            ++l;
-        }
+    read = total = 0;
+    begin = left = buf;
+    while (total < bufsize && (read = fread(left, sizeof(*left), bufsize-total, fptr))) {
+        total += read;
+        end = buf + total;
+        for (right = left; right < end; ++right)
+            if (*right != '\n')
+                *left++ = *right;
+        total -= right - left;
+    }
+    if (left > begin) {
+        for (--left; *left == PADDING; --left)
+            ;
+        ++left;
     }
 
-    return l-sbeg;
+    return left-begin;
 }

input.h

@@ -4,6 +4,6 @@
 #include <stdio.h>
 
 int
-readb(FILE *fp, unsigned char *s, int slen);
+readb(FILE *fptr, unsigned char *buf, int bufsize);
 
 #endif

output.c

@@ -3,35 +3,35 @@
 #define WRAPCOL 76
 
 char
-printw(FILE *fp, unsigned char *s, int slen)
+printw(FILE *fptr, unsigned char *buf, int bufsize)
 {
-    static int col;
+    static int column;
     int c;
 
     c = '\n';
-    if (col) {
-        if (slen >= WRAPCOL-col) {
-            fwrite(s, sizeof(*s), WRAPCOL-col, fp);
-            s += WRAPCOL-col;
-            slen -= WRAPCOL-col;
-            col = 0;
-            fputc('\n', fp);
+    if (column > 0) {
+        if (bufsize >= WRAPCOL-column) {
+            fwrite(buf, sizeof(*buf), WRAPCOL-column, fptr);
+            buf += WRAPCOL-column;
+            bufsize -= WRAPCOL-column;
+            column = 0;
+            fputc('\n', fptr);
         } else {
-            fwrite(s, sizeof(*s), slen, fp);
-            s += slen;
-            col += slen;
-            slen -= slen;
-            c = *(s+slen-1);
+            fwrite(buf, sizeof(*buf), bufsize, fptr);
+            column += bufsize;
+            buf += bufsize;
+            bufsize -= bufsize;
+            c = *(buf+bufsize-1);
         }
     }
-    for (; slen >= WRAPCOL; slen -= WRAPCOL, s += WRAPCOL) {
-        fwrite(s, sizeof(*s), WRAPCOL, fp);
-        fputc('\n', fp);
+    for (; bufsize >= WRAPCOL; bufsize -= WRAPCOL, buf += WRAPCOL) {
+        fwrite(buf, sizeof(*buf), WRAPCOL, fptr);
+        fputc('\n', fptr);
     }
-    if (slen > 0) {
-        fwrite(s, sizeof(*s), slen, fp);
-        col += slen;
-        c = *(s+slen-1);
+    if (bufsize > 0) {
+        fwrite(buf, sizeof(*buf), bufsize, fptr);
+        column += bufsize;
+        c = *(buf+bufsize-1);
     }
 
     return c;

output.h

@@ -4,6 +4,6 @@
 #include <stdio.h>
 
 char
-printw(FILE *fp, unsigned char *s, int slen);
+printw(FILE *fptr, unsigned char *buf, int bufsize);
 
 #endif