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90 lines
1.9 KiB
C

#include <io_internal.h>
#include <iob.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/mman.h>
#define BUFSIZE 16384
int64 io_mmapwritefile(int64 out,int64 in,uint64 off,uint64 bytes,io_write_callback writecb) {
char buf[BUFSIZE];
int n,m;
uint64 sent=0;
io_entry* e=array_get(&io_fds,sizeof(io_entry),out);
if (e) {
const char* c;
long left;
do {
if (e->mmapped) {
/* did we already map the right chunk? */
if (off>=e->mapofs && off<e->mapofs+e->maplen)
goto mapok; /* ok; mmapped the right chunk*/
munmap(e->mmapped,e->maplen);
}
e->mapofs=off&0xffffffffffff0000ull;
if (e->mapofs+0x10000>off+bytes)
e->maplen=off+bytes-e->mapofs;
else
e->maplen=0x10000;
if ((e->mmapped=mmap(0,e->maplen,PROT_READ,MAP_SHARED,in,e->mapofs))==MAP_FAILED) {
e->mmapped=0;
goto readwrite;
}
mapok:
c=(const char*)(e->mmapped)+(off&0xffff);
left=e->maplen-(off&0xffff);
if (left>bytes) left=bytes;
while (left>0) {
m=writecb(out,c,left);
if (m==-1) {
e->canwrite=0;
e->next_write=-1;
if (errno!=EAGAIN) {
munmap(e->mmapped,e->maplen);
e->mmapped=0;
return -3;
}
return sent?sent:-1;
}
if (m==0) return sent;
sent+=m;
left-=m;
bytes-=m;
off+=m;
c+=m;
}
} while (bytes);
if (e->mmapped) {
munmap(e->mmapped,e->maplen);
e->mmapped=0;
}
return sent;
}
readwrite:
if (lseek(in,off,SEEK_SET) != off)
return -1;
while (bytes>0) {
char* tmp=buf;
if ((n=read(in,tmp,(bytes<BUFSIZE)?bytes:BUFSIZE))<=0)
return (sent?sent:-1);
while (n>0) {
if ((m=writecb(out,tmp,n))<0) {
if (m==-1) {
if (e) {
e->canwrite=0;
e->next_write=-1;
}
return errno==EAGAIN?(sent?sent:-1):-3;
}
goto abort;
}
sent+=m;
n-=m;
bytes-=m;
tmp+=m;
}
}
abort:
return sent;
}