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-rw-r--r--libbio/brdstr.c112
1 files changed, 112 insertions, 0 deletions
diff --git a/libbio/brdstr.c b/libbio/brdstr.c
new file mode 100644
index 0000000..ce720c2
--- /dev/null
+++ b/libbio/brdstr.c
@@ -0,0 +1,112 @@
+#include <stdlib.h>
+#include <plan9.h>
+#include <bio.h>
+
+static char*
+badd(char *p, int *np, char *data, int ndata, int delim, int nulldelim)
+{
+ int n;
+
+ n = *np;
+ p = realloc(p, n+ndata+1);
+ if(p){
+ memmove(p+n, data, ndata);
+ n += ndata;
+ if(n>0 && nulldelim && p[n-1]==delim)
+ p[--n] = '\0';
+ else
+ p[n] = '\0';
+ *np = n;
+ }
+ return p;
+}
+
+char*
+Brdstr(Biobuf *bp, int delim, int nulldelim)
+{
+ char *ip, *ep, *p;
+ int i, j;
+
+ i = -bp->icount;
+ bp->rdline = 0;
+ if(i == 0) {
+ /*
+ * eof or other error
+ */
+ if(bp->state != Bractive) {
+ if(bp->state == Bracteof)
+ bp->state = Bractive;
+ bp->gbuf = bp->ebuf;
+ return nil;
+ }
+ }
+
+ /*
+ * first try in remainder of buffer (gbuf doesn't change)
+ */
+ ip = (char*)bp->ebuf - i;
+ ep = memchr(ip, delim, i);
+ if(ep) {
+ j = (ep - ip) + 1;
+ bp->icount += j;
+ return badd(nil, &bp->rdline, ip, j, delim, nulldelim);
+ }
+
+ /*
+ * copy data to beginning of buffer
+ */
+ if(i < bp->bsize)
+ memmove(bp->bbuf, ip, i);
+ bp->gbuf = bp->bbuf;
+
+ /*
+ * append to buffer looking for the delim
+ */
+ p = nil;
+ for(;;){
+ ip = (char*)bp->bbuf + i;
+ while(i < bp->bsize) {
+ j = read(bp->fid, ip, bp->bsize-i);
+ if(j <= 0 && i == 0)
+ return p;
+ if(j <= 0 && i > 0){
+ /*
+ * end of file but no delim. pretend we got a delim
+ * by making the delim \0 and smashing it with nulldelim.
+ */
+ j = 1;
+ ep = ip;
+ delim = '\0';
+ nulldelim = 1;
+ *ep = delim; /* there will be room for this */
+ }else{
+ bp->offset += j;
+ ep = memchr(ip, delim, j);
+ }
+ i += j;
+ if(ep) {
+ /*
+ * found in new piece
+ * copy back up and reset everything
+ */
+ ip = (char*)bp->ebuf - i;
+ if(i < bp->bsize){
+ memmove(ip, bp->bbuf, i);
+ bp->gbuf = (unsigned char*)ip;
+ }
+ j = (ep - (char*)bp->bbuf) + 1;
+ bp->icount = j - i;
+ return badd(p, &bp->rdline, ip, j, delim, nulldelim);
+ }
+ ip += j;
+ }
+
+ /*
+ * full buffer without finding; add to user string and continue
+ */
+ p = badd(p, &bp->rdline, (char*)bp->bbuf, bp->bsize, 0, 0);
+ i = 0;
+ bp->icount = 0;
+ bp->gbuf = bp->ebuf;
+ }
+}