64 lines
1.4 KiB
C
64 lines
1.4 KiB
C
#define _GNU_SOURCE
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#include <stdlib.h>
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#include <unistd.h>
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#include <sys/mman.h>
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#include <sys/fcntl.h>
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#include <sys/shm.h>
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#include <stdio.h>
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#include "byte.h"
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#include "mstorage.h"
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#ifndef PAGE_SIZE
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#define PAGE_SIZE 4096
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#endif
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#define PAGEMASK ((PAGE_SIZE)-1)
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/* Sadly, mremap is only available on Linux */
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/* Please petition your congressman^Woperating system vendor to include it! */
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long mstorage_add(mstorage_t* p,const char* s,unsigned long n) {
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if (p->mapped-p->used<n) {
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if (!p->root) {
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/* nothing allocated. mmap /dev/zero */
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char* tmp;
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long need=(n|PAGEMASK)+1;
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#ifdef MREMAP_MAYMOVE
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#ifdef MAP_ANONYMOUS
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if ((tmp=mmap(0,need,PROT_READ|PROT_WRITE,MAP_PRIVATE|MAP_ANONYMOUS,-1,0))==MAP_FAILED)
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return -1;
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#else
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int fd=open("/dev/zero",O_RDWR);
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if (fd<0) return -1;
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tmp=mmap(0,need,PROT_READ|PROT_WRITE,MAP_PRIVATE,fd,0);
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close(fd);
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if (tmp==MAP_FAILED)
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return -1;
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#endif
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#else
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if (!(tmp=malloc(need)))
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return -1;
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#endif
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p->root=tmp;
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p->mapped=need;
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p->used=0;
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} else {
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long need=((p->used+n)|PAGEMASK)+1;
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#ifdef MREMAP_MAYMOVE
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char* tmp=mremap(p->root,p->mapped,need,MREMAP_MAYMOVE);
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if (tmp==MAP_FAILED) return -1;
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#else
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char* tmp=realloc(p->root,need);
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if (!tmp) return -1;
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#endif
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p->mapped=need; p->root=tmp;
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}
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}
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byte_copy(p->root+p->used,n,s);
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{
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unsigned long l=p->used;
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p->used+=n;
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return l;
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}
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}
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