Move BBS non-related functions to independent library

git-svn-id: http://opensvn.csie.org/pttbbs/trunk/pttbbs@4350 63ad8ddf-47c3-0310-b6dd-a9e9d9715204

2 files changed, 195 insertions, 1 deletions

diff --git a/common/sys/Makefile b/common/sys/Makefile
index 39598f86..e0fec71f 100644
--- a/common/sys/Makefile
+++ b/common/sys/Makefile
@@ -5,7 +5,7 @@ MKPIC:=no
 SRCROOT=	../..
 .include "$(SRCROOT)/pttbbs.mk"
 
-SRCS:=	file.c lock.c log.c net.c sort.c string.c time.c crypt.c osdep.c
+SRCS:=	file.c lock.c log.c net.c sort.c string.c time.c crypt.c record.c osdep.c
 LIB:=	cmsys
 
 install:
diff --git a/common/sys/record.c b/common/sys/record.c
new file mode 100644
index 00000000..e1b74402
--- /dev/null
+++ b/common/sys/record.c
@@ -0,0 +1,194 @@
+/* $Id$ */
+
+#include <sys/stat.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <assert.h>
+#include "cmsys.h"
+
+#define BUFSIZE 512
+
+/* Functions for fixed size record operations */
+
+int
+get_num_records(const char *fpath, size_t size)
+{
+    struct stat st;
+
+    if (stat(fpath, &st) == -1)
+	return 0;
+
+    return st.st_size / size;
+}
+
+int
+get_records_keep(const char *fpath, void *rptr, size_t size, int id, size_t number, int *fd)
+{
+    assert(fpath);
+    assert(fd);
+
+    if (id < 1)
+	return -1;
+
+    if (*fd < 0 && (*fd = open(fpath, O_RDONLY, 0)) == -1)
+	return -1;
+
+    if (lseek(*fd, (off_t) (size * (id - 1)), SEEK_SET) == -1)
+	return 0;
+
+    if ((id = read(*fd, rptr, size * number)) == -1)
+	return -1;
+
+    return id / size;
+}
+
+int
+get_records(const char *fpath, void *rptr, size_t size, int id, size_t number)
+{
+    int res, fd = -1;
+
+    res = get_records_keep(fpath, rptr, size, id, number, &fd);
+    close(fd);
+
+    return res;
+}
+
+#ifndef get_record
+int
+get_record(const char *fpath, void *rptr, size_t size, int id)
+{
+    return get_records(fpath, rptr, size, id, 1);
+}
+#endif
+
+#ifndef get_record_keep
+int
+get_record_keep(const char *fpath, void *rptr, size_t size, int id, int *fd)
+{
+    return get_records_keep(fpath, rptr, size, id, 1, fd);
+}
+#endif
+
+int
+substitute_record(const char *fpath, const void *rptr, size_t size, int id)
+{
+    int fd;
+    off_t offset = size * (id - 1);
+
+    if (id < 1 || (fd = open(fpath, O_WRONLY | O_CREAT, 0644)) == -1)
+	return -1;
+
+    lseek(fd, offset, SEEK_SET);
+    PttLock(fd, offset, size, F_WRLCK);
+    write(fd, rptr, size);
+    PttLock(fd, offset, size, F_UNLCK);
+    close(fd);
+
+    return 0;
+}
+
+int
+append_record(const char *fpath, const void *record, size_t size)
+{
+    int fd, index = -2, fsize = 0;
+
+    if ((fd = open(fpath, O_WRONLY | O_CREAT, 0644)) == -1)
+	return -1;
+
+    flock(fd, LOCK_EX);
+
+    if ((fsize = lseek(fd, 0, SEEK_END)) < 0)
+	goto out;
+
+    index = fsize / size;
+    lseek(fd, index * size, SEEK_SET);  // avoid offset
+
+    write(fd, record, size);
+
+out:
+    flock(fd, LOCK_UN);
+    close(fd);
+
+    return index + 1;
+}
+
+int
+delete_records(const char *fpath, size_t size, int id, size_t num)
+{
+    char buf[BUFSIZE];
+    int fi, fo, locksize, readsize, c, d=0;
+    struct stat st;
+    off_t offset = size * (id - 1);
+
+    if ((fi=open(fpath, O_RDONLY, 0)) == -1)
+	return -1;
+
+    if ((fo=open(fpath, O_WRONLY, 0)) == -1) {
+	close(fi);
+	return -1;
+    }
+
+    if (fstat(fi, &st)==-1) {
+	close(fo);
+	close(fi);
+	return -1;
+    }
+
+    locksize = st.st_size - offset;
+    readsize = locksize - size*num;
+
+    if (locksize < 0 ) {
+	close(fo);
+	close(fi);
+	return -1;
+    }
+
+    PttLock(fo, offset, locksize, F_WRLCK);
+
+    if (readsize > 0) {
+	lseek(fi, offset+size, SEEK_SET);  
+	lseek(fo, offset, SEEK_SET);  
+	while (d < readsize && (c = read(fi, buf, BUFSIZE)) > 0) {
+	    write(fo, buf, c);
+	    d += c;
+	}
+    }
+    close(fi);
+
+    ftruncate(fo, st.st_size - size*num);
+
+    PttLock(fo, offset, locksize, F_UNLCK);
+
+    close(fo);
+
+    return 0;
+}
+
+#ifndef delete_record
+int delete_record(const char *fpath, size_t size, int id)
+{
+    return delete_records(fpath, size, id, 1);
+}
+#endif
+
+int
+apply_record(const char *fpath, int (*fptr) (void *item, void *optarg), size_t size, void *arg)
+{
+    char buf[BUFSIZE];
+    int fd;
+
+    assert(size <= sizeof(buf));
+
+    if ((fd = open(fpath, O_RDONLY, 0)) == -1)
+	return -1;
+
+    while (read(fd, buf, size) == size)
+	if ((*fptr) (buf, arg) == 1) {
+	    close(fd);
+	    return 1;
+	}
+
+    close(fd);
+
+    return 0;
+}