/*
* __wt_handle_search --
* Search for a matching handle.
*/
bool
__wt_handle_search(WT_SESSION_IMPL *session,
const char *name, bool increment_ref, WT_FH *newfh, WT_FH **fhp)
{
WT_CONNECTION_IMPL *conn;
WT_FH *fh;
uint64_t bucket, hash;
bool found;
if (fhp != NULL)
*fhp = NULL;
conn = S2C(session);
found = false;
hash = __wt_hash_city64(name, strlen(name));
bucket = hash % WT_HASH_ARRAY_SIZE;
__wt_spin_lock(session, &conn->fh_lock);
/*
* If we already have the file open, optionally increment the reference
* count and return a pointer.
*/
TAILQ_FOREACH(fh, &conn->fhhash[bucket], hashq)
if (strcmp(name, fh->name) == 0) {
if (increment_ref)
++fh->ref;
if (fhp != NULL)
*fhp = fh;
found = true;
break;
}
/* If we don't find a match, optionally add a new entry. */
if (!found && newfh != NULL) {
newfh->name_hash = hash;
WT_CONN_FILE_INSERT(conn, newfh, bucket);
(void)__wt_atomic_add32(&conn->open_file_count, 1);
if (increment_ref)
++newfh->ref;
if (fhp != NULL)
*fhp = newfh;
}
__wt_spin_unlock(session, &conn->fh_lock);
return (found);
}
/*
* __wt_open --
* Open a file handle.
*/
int
__wt_open(WT_SESSION_IMPL *session,
const char *name, int ok_create, int exclusive, int dio_type, WT_FH **fhp)
{
DWORD dwCreationDisposition;
HANDLE filehandle, filehandle_secondary;
WT_CONNECTION_IMPL *conn;
WT_DECL_RET;
WT_FH *fh, *tfh;
uint64_t bucket, hash;
int direct_io, f, matched, share_mode;
char *path;
conn = S2C(session);
fh = NULL;
path = NULL;
filehandle = INVALID_HANDLE_VALUE;
filehandle_secondary = INVALID_HANDLE_VALUE;
direct_io = 0;
hash = __wt_hash_city64(name, strlen(name));
bucket = hash % WT_HASH_ARRAY_SIZE;
WT_RET(__wt_verbose(session, WT_VERB_FILEOPS, "%s: open", name));
/* Increment the reference count if we already have the file open. */
matched = 0;
__wt_spin_lock(session, &conn->fh_lock);
SLIST_FOREACH(tfh, &conn->fhhash[bucket], l)
if (strcmp(name, tfh->name) == 0) {
++tfh->ref;
*fhp = tfh;
matched = 1;
break;
}
__wt_spin_unlock(session, &conn->fh_lock);
if (matched)
return (0);
/* For directories, create empty file handles with invalid handles */
if (dio_type == WT_FILE_TYPE_DIRECTORY) {
goto setupfh;
}
WT_RET(__wt_filename(session, name, &path));
share_mode = FILE_SHARE_READ | FILE_SHARE_WRITE;
/*
* Security:
* The application may spawn a new process, and we don't want another
* process to have access to our file handles.
*
* TODO: Set tighter file permissions but set bInheritHandle to false
* to prevent inheritance
*/
f = FILE_ATTRIBUTE_NORMAL;
dwCreationDisposition = 0;
if (ok_create) {
dwCreationDisposition = CREATE_NEW;
if (exclusive)
dwCreationDisposition = CREATE_ALWAYS;
} else
dwCreationDisposition = OPEN_EXISTING;
if (dio_type && FLD_ISSET(conn->direct_io, dio_type)) {
f |= FILE_FLAG_NO_BUFFERING | FILE_FLAG_WRITE_THROUGH;
direct_io = 1;
}
if (dio_type == WT_FILE_TYPE_LOG &&
FLD_ISSET(conn->txn_logsync, WT_LOG_DSYNC)) {
f |= FILE_FLAG_WRITE_THROUGH;
}
/* Disable read-ahead on trees: it slows down random read workloads. */
if (dio_type == WT_FILE_TYPE_DATA ||
dio_type == WT_FILE_TYPE_CHECKPOINT)
f |= FILE_FLAG_RANDOM_ACCESS;
filehandle = CreateFileA(path,
(GENERIC_READ | GENERIC_WRITE),
share_mode,
NULL,
dwCreationDisposition,
f,
NULL);
if (filehandle == INVALID_HANDLE_VALUE) {
if (GetLastError() == ERROR_FILE_EXISTS && ok_create)
filehandle = CreateFileA(path,
(GENERIC_READ | GENERIC_WRITE),
share_mode,
NULL,
OPEN_EXISTING,
f,
NULL);
if (filehandle == INVALID_HANDLE_VALUE)
WT_ERR_MSG(session, __wt_errno(),
direct_io ?
"%s: open failed with direct I/O configured, some "
"filesystem types do not support direct I/O" :
"%s", path);
}
/*
* Open a second handle to file to support allocation/truncation
* concurrently with reads on the file. Writes would also move the file
* pointer.
*/
filehandle_secondary = CreateFileA(path,
(GENERIC_READ | GENERIC_WRITE),
share_mode,
NULL,
OPEN_EXISTING,
f,
NULL);
if (filehandle == INVALID_HANDLE_VALUE)
WT_ERR_MSG(session, __wt_errno(),
"open failed for secondary handle: %s", path);
setupfh:
WT_ERR(__wt_calloc_one(session, &fh));
WT_ERR(__wt_strdup(session, name, &fh->name));
fh->name_hash = hash;
fh->filehandle = filehandle;
fh->filehandle_secondary = filehandle_secondary;
fh->ref = 1;
fh->direct_io = direct_io;
/* Set the file's size. */
if (dio_type != WT_FILE_TYPE_DIRECTORY)
WT_ERR(__wt_filesize(session, fh, &fh->size));
/* Configure file extension. */
if (dio_type == WT_FILE_TYPE_DATA ||
dio_type == WT_FILE_TYPE_CHECKPOINT)
fh->extend_len = conn->data_extend_len;
/* Configure fallocate/posix_fallocate calls. */
__wt_fallocate_config(session, fh);
/*
* Repeat the check for a match, but then link onto the database's list
* of files.
*/
matched = 0;
__wt_spin_lock(session, &conn->fh_lock);
SLIST_FOREACH(tfh, &conn->fhhash[bucket], l)
if (strcmp(name, tfh->name) == 0) {
++tfh->ref;
*fhp = tfh;
matched = 1;
break;
}
if (!matched) {
WT_CONN_FILE_INSERT(conn, fh, bucket);
WT_STAT_FAST_CONN_INCR(session, file_open);
*fhp = fh;
}
__wt_spin_unlock(session, &conn->fh_lock);
if (matched) {
err: if (fh != NULL) {
__wt_free(session, fh->name);
__wt_free(session, fh);
}
if (filehandle != INVALID_HANDLE_VALUE)
(void)CloseHandle(filehandle);
if (filehandle_secondary != INVALID_HANDLE_VALUE)
(void)CloseHandle(filehandle_secondary);
}
__wt_free(session, path);
return (ret);
}
