| #include "lib9.h" | |
| #include <bio.h> | |
| int | |
| Bgetc(Biobuf *bp) | |
| { | |
| int i; | |
| loop: | |
| i = bp->icount; | |
| if(i != 0) { | |
| bp->icount = i+1; | |
| return bp->ebuf[i]; | |
| } | |
| if(bp->state != Bractive) { | |
| if(bp->state == Bracteof) | |
| bp->state = Bractive; | |
| return Beof; | |
| } | |
| /* | |
| * get next buffer, try to keep Bungetsize | |
| * characters pre-catenated from the previous | |
| * buffer to allow that many ungets. | |
| */ | |
| memmove(bp->bbuf-Bungetsize, bp->ebuf-Bungetsize, Bungetsize); | |
| i = read(bp->fid, bp->bbuf, bp->bsize); | |
| bp->gbuf = bp->bbuf; | |
| if(i <= 0) { | |
| if(i < 0) | |
| bp->state = Binactive; | |
| return Beof; | |
| } | |
| if(i < bp->bsize) { | |
| memmove(bp->ebuf-i-Bungetsize, bp->bbuf-Bungetsize, i+Bungetsize); | |
| bp->gbuf = bp->ebuf-i; | |
| } | |
| bp->icount = -i; | |
| bp->offset += i; | |
| goto loop; | |
| } | |
| int | |
| Bungetc(Biobuf *bp) | |
| { | |
| if(bp->state == Bracteof) | |
| bp->state = Bractive; | |
| if(bp->state != Bractive) | |
| return Beof; | |
| bp->icount--; | |
| return 1; | |
| } |