os_rw.c
上传用户:romrleung
上传日期:2022-05-23
资源大小:18897k
文件大小:4k
- /*-
- * See the file LICENSE for redistribution information.
- *
- * Copyright (c) 1997-2002
- * Sleepycat Software. All rights reserved.
- */
- #include "db_config.h"
- #ifndef lint
- static const char revid[] = "$Id: os_rw.c,v 11.28 2002/08/06 04:56:19 bostic Exp $";
- #endif /* not lint */
- #ifndef NO_SYSTEM_INCLUDES
- #include <sys/types.h>
- #include <string.h>
- #include <unistd.h>
- #endif
- #include "db_int.h"
- /*
- * __os_io --
- * Do an I/O.
- *
- * PUBLIC: int __os_io __P((DB_ENV *, DB_IO *, int, size_t *));
- */
- int
- __os_io(dbenv, db_iop, op, niop)
- DB_ENV *dbenv;
- DB_IO *db_iop;
- int op;
- size_t *niop;
- {
- int ret;
- if (__os_is_winnt()) {
- ULONG64 off = (ULONG64)db_iop->pagesize * db_iop->pgno;
- OVERLAPPED over;
- DWORD nbytes;
- over.Offset = (DWORD)(off & 0xffffffff);
- over.OffsetHigh = (DWORD)(off >> 32);
- over.hEvent = 0; /* we don't want asynchronous notifications */
- switch (op) {
- case DB_IO_READ:
- if (DB_GLOBAL(j_read) != NULL)
- goto slow;
- if (!ReadFile(db_iop->fhp->handle,
- db_iop->buf, (DWORD)db_iop->bytes, &nbytes, &over))
- goto slow;
- break;
- case DB_IO_WRITE:
- if (DB_GLOBAL(j_write) != NULL)
- goto slow;
- if (!WriteFile(db_iop->fhp->handle,
- db_iop->buf, (DWORD)db_iop->bytes, &nbytes, &over))
- goto slow;
- break;
- }
- if (nbytes == db_iop->bytes) {
- *niop = (size_t)nbytes;
- return (0);
- }
- }
- slow: MUTEX_THREAD_LOCK(dbenv, db_iop->mutexp);
- if ((ret = __os_seek(dbenv, db_iop->fhp,
- db_iop->pagesize, db_iop->pgno, 0, 0, DB_OS_SEEK_SET)) != 0)
- goto err;
- switch (op) {
- case DB_IO_READ:
- ret = __os_read(dbenv,
- db_iop->fhp, db_iop->buf, db_iop->bytes, niop);
- break;
- case DB_IO_WRITE:
- ret = __os_write(dbenv,
- db_iop->fhp, db_iop->buf, db_iop->bytes, niop);
- break;
- }
- err: MUTEX_THREAD_UNLOCK(dbenv, db_iop->mutexp);
- return (ret);
- }
- /*
- * __os_read --
- * Read from a file handle.
- *
- * PUBLIC: int __os_read __P((DB_ENV *, DB_FH *, void *, size_t, size_t *));
- */
- int
- __os_read(dbenv, fhp, addr, len, nrp)
- DB_ENV *dbenv;
- DB_FH *fhp;
- void *addr;
- size_t len;
- size_t *nrp;
- {
- size_t offset;
- DWORD nr;
- int ret;
- BOOL success;
- u_int8_t *taddr;
- for (taddr = addr,
- offset = 0; offset < len; taddr += nr, offset += nr) {
- retry: if (DB_GLOBAL(j_read) != NULL) {
- nr = (DWORD)DB_GLOBAL(j_read)(fhp->fd,
- taddr, len - offset);
- success = (nr >= 0);
- } else {
- success = ReadFile(fhp->handle,
- taddr, (DWORD)(len - offset), &nr, NULL);
- if (!success)
- __os_set_errno(__os_win32_errno());
- }
- if (!success) {
- if ((ret = __os_get_errno()) == EINTR)
- goto retry;
- __db_err(dbenv, "read: 0x%lx, %lu: %s",
- P_TO_ULONG(taddr),
- (u_long)len - offset, strerror(ret));
- return (ret);
- }
- if (nr == 0)
- break;
- }
- *nrp = taddr - (u_int8_t *)addr;
- return (0);
- }
- /*
- * __os_write --
- * Write to a file handle.
- *
- * PUBLIC: int __os_write __P((DB_ENV *, DB_FH *, void *, size_t, size_t *));
- */
- int
- __os_write(dbenv, fhp, addr, len, nwp)
- DB_ENV *dbenv;
- DB_FH *fhp;
- void *addr;
- size_t len;
- size_t *nwp;
- {
- size_t offset;
- DWORD nw;
- int ret;
- BOOL success;
- u_int8_t *taddr;
- for (taddr = addr,
- offset = 0; offset < len; taddr += nw, offset += nw) {
- retry: if (DB_GLOBAL(j_write) != NULL) {
- nw = (DWORD)DB_GLOBAL(j_write)(fhp->fd,
- taddr, len - offset);
- success = (nw >= 0);
- } else {
- success = WriteFile(fhp->handle,
- taddr, (DWORD)(len - offset), &nw, NULL);
- if (!success)
- __os_set_errno(__os_win32_errno());
- }
- if (!success) {
- if ((ret = __os_get_errno()) == EINTR)
- goto retry;
- __db_err(dbenv, "write: 0x%x, %lu: %s", taddr,
- (u_long)len-offset, strerror(ret));
- return (ret);
- }
- }
- *nwp = len;
- return (0);
- }