/* $Id$ */
#include "bbs.h"
/**
* 關於本檔案的細節,請見 docs/brc.txt。
* v3: add last modified time for comment system. double max size.
* original time_t as 'create'.
*/
#ifndef BRC_MAXNUM
#define BRC_STRLEN 15 /* Length of board name, for old brc */
#define BRC_MAXSIZE 49152 /* Effective size of brc rc file, 8192 * 3 * 2 */
#define BRC_MAXNUM 80 /* Upper bound of brc_num, size of brc_list */
#endif
#define BRC_BLOCKSIZE 1024
#if MAX_BOARD > 65535 || BRC_MAXSIZE > 65535
#error Max number of boards or BRC_MAXSIZE cannot fit in unsigned short, \
please rewrite brc.c
#endif
typedef unsigned short brcbid_t;
typedef unsigned short brcnbrd_t;
typedef struct {
time4_t create;
time4_t modified;
} brc_rec;
/* old brc rc file form:
* board_name 15 bytes
* brc_num 1 byte, binary integer
* brc_list brc_num * sizeof(brc_rec) bytes */
static char brc_initialized = 0;
static time4_t brc_expire_time;
/* Will be set to the time one year before login. All the files created
* before then will be recognized read. */
static int brc_changed = 0; /**< brc_list/brc_num changed */
/* The below two will be filled by read_brc_buf() and brc_update() */
static char *brc_buf = NULL;
static int brc_size;
static int brc_alloc;
// read records for currbid
static int brc_currbid;
static int brc_num;
static brc_rec brc_list[BRC_MAXNUM];
static char * const fn_brc2= ".brc2";
static char * const fn_brc = ".brc3";
/**
* find read records of bid in given buffer region
*
* @param[in] begin
* @param[in] endp
* @param bid
* @param[out] num number of records, which could be written for \a bid
* = brc_num if found
* = 0 or dangling size if not found
*
* @return address of record. \a begin <= addr < \a endp.
* 0 if not found
*/
/* Returns the address of the record strictly between begin and endp with
* bid equal to the parameter. Returns 0 if not found.
* brcnbrd_t *num is an output parameter which will filled with brc_num
* if the record is found. If not found the record, *num will be the number
* of dangling bytes. */
static char *
brc_findrecord_in(char *begin, char *endp, brcbid_t bid, brcnbrd_t *num)
{
char *tmpp, *ptr = begin;
brcbid_t tbid;
while (ptr + sizeof(brcbid_t) + sizeof(brcnbrd_t) < endp) {
/* for each available records */
tmpp = ptr;
tbid = *(brcbid_t*)tmpp;
tmpp += sizeof(brcbid_t);
*num = *(brcnbrd_t*)tmpp;
tmpp += sizeof(brcnbrd_t) + *num * sizeof(brc_rec); /* end of record */
if ( tmpp > endp ){
/* dangling, ignore the trailing data */
*num = (brcnbrd_t)(endp - ptr); /* for brc_insert_record() */
return 0;
}
if ( tbid == bid )
return ptr;
ptr = tmpp;
}
*num = 0;
return 0;
}
static brc_rec *
brc_find_record(int bid, int *num)
{
char *p;
brcnbrd_t tnum;
p = brc_findrecord_in(brc_buf, brc_buf + brc_size, bid, &tnum);
*num = tnum;
if (p)
return (brc_rec*)(p + sizeof(brcbid_t) + sizeof(brcnbrd_t));
*num = 0;
return 0;
}
static char *
brc_putrecord(char *ptr, char *endp, brcbid_t bid,
brcnbrd_t num, const brc_rec *list)
{
char * tmp;
if (num > 0 && list[0].create > brc_expire_time &&
ptr + sizeof(brcbid_t) + sizeof(brcnbrd_t) < endp) {
if (num > BRC_MAXNUM)
num = BRC_MAXNUM;
if (num == 0) return ptr;
*(brcbid_t*)ptr = bid; /* write in bid */
ptr += sizeof(brcbid_t);
*(brcnbrd_t*)ptr = num; /* write in brc_num */
ptr += sizeof(brcnbrd_t);
tmp = ptr + num * sizeof(brc_rec);
if (tmp <= endp)
memcpy(ptr, list, num * sizeof(brc_rec)); /* write in brc_list */
ptr = tmp;
}
return ptr;
}
static inline int
brc_enlarge_buf(void)
{
char *buffer;
if (brc_alloc >= BRC_MAXSIZE)
return 0;
#ifdef CRITICAL_MEMORY
#define THE_MALLOC(X) MALLOC(X)
#define THE_FREE(X) FREE(X)
#else
#define THE_MALLOC(X) alloca(X)
#define THE_FREE(X) (void)(X)
/* alloca get memory from stack and automatically freed when
* function returns. */
#endif
buffer = (char*)THE_MALLOC(brc_alloc);
assert(buffer);
memcpy(buffer, brc_buf, brc_alloc);
free(brc_buf);
brc_alloc += BRC_BLOCKSIZE;
brc_buf = (char*)malloc(brc_alloc);
assert(brc_buf);
memcpy(brc_buf, buffer, brc_alloc - BRC_BLOCKSIZE);
#ifdef DEBUG
vmsgf("brc enlarged to %d bytes", brc_alloc);
#endif
THE_FREE(buffer);
return 1;
#undef THE_MALLOC
#undef THE_FREE
}
static inline void
brc_get_buf(int size){
if (!size)
brc_alloc = BRC_BLOCKSIZE;
else
brc_alloc = (size + BRC_BLOCKSIZE - 1) / BRC_BLOCKSIZE * BRC_BLOCKSIZE;
if (brc_alloc > BRC_MAXSIZE)
brc_alloc = BRC_MAXSIZE;
brc_buf = (char*)malloc(brc_alloc);
assert(brc_buf);
}
static inline void
brc_insert_record(brcbid_t bid, brcnbrd_t num, const brc_rec* list)
{
char *ptr;
int new_size, end_size;
brcnbrd_t tnum;
ptr = brc_findrecord_in(brc_buf, brc_buf + brc_size, bid, &tnum);
while (num > 0 && list[num - 1].create < brc_expire_time)
num--; /* don't write the times before brc_expire_time */
if (!ptr) {
brc_size -= (int)tnum;
/* put on the beginning */
if (num){
new_size = sizeof(brcbid_t) + sizeof(brcnbrd_t)
+ num * sizeof(brc_rec);
brc_size += new_size;
if (brc_size > brc_alloc && !brc_enlarge_buf())
brc_size = BRC_MAXSIZE;
if (brc_size > new_size)
memmove(brc_buf + new_size, brc_buf, brc_size - new_size);
brc_putrecord(brc_buf, brc_buf + new_size, bid, num, list);
}
} else {
/* ptr points to the old current brc list.
* tmpp is the end of it (exclusive). */
int len = sizeof(brcbid_t) + sizeof(brcnbrd_t) + tnum * sizeof(brc_rec);
char *tmpp = ptr + len;
end_size = brc_buf + brc_size - tmpp;
if (num) {
int sindex = ptr - brc_buf;
new_size = (sizeof(brcbid_t) + sizeof(brcnbrd_t)
+ num * sizeof(brc_rec));
brc_size += new_size - len;
if (brc_size > brc_alloc) {
if (brc_enlarge_buf()) {
ptr = brc_buf + sindex;
tmpp = ptr + len;
} else {
end_size -= brc_size - BRC_MAXSIZE;
brc_size = BRC_MAXSIZE;
}
}
if (end_size > 0 && ptr + new_size != tmpp)
memmove(ptr + new_size, tmpp, end_size);
brc_putrecord(ptr, brc_buf + brc_alloc, bid, num, list);
} else { /* deleting record */
memmove(ptr, tmpp, end_size);
brc_size -= len;
}
}
brc_changed = 0;
}
/**
* write \a brc_num and \a brc_list back to \a brc_buf.
*/
void
brc_update(){
if (brc_currbid && brc_changed && cuser.userlevel && brc_num > 0) {
brc_initialize();
brc_insert_record(brc_currbid, brc_num, brc_list);
}
}
static void
read_brc2(void)
{
char brcfile[STRLEN];
int fd;
size_t sz2 = 0, sz3 = 0;
char *cvt = NULL, *cvthead = NULL;
brcbid_t bid;
brcnbrd_t num;
time4_t create;
brc_rec rec;
setuserfile(brcfile, fn_brc2);
if ((fd = open(brcfile, O_RDONLY)) == -1)
return;
sz2 = dashs(brcfile);
sz3 = sz2 * 2; // max double size
cvthead = cvt = malloc (sz3);
// now calculate real sz3
while (read(fd, &bid, sizeof(bid)) > 0)
{
if (read(fd, &num, sizeof(num)) < 1)
break;
*(brcbid_t*)cvt = bid; cvt += sizeof(brcbid_t);
*(brcnbrd_t*)cvt = num;cvt += sizeof(brcnbrd_t);
for (; num > 0; num--)
{
read(fd, &create, sizeof(create));
rec.create = create;
rec.modified = create;
*(brc_rec*)cvt = rec; cvt += sizeof(brc_rec);
}
}
close(fd);
// now cvthead is ready for v3.
sz3 = cvt - cvthead;
brc_get_buf(sz3);
brc_size = sz3;
memcpy(brc_buf, cvthead, sz3);
free(cvthead);
}
inline static void
read_brc_buf(void)
{
char brcfile[STRLEN];
int fd;
struct stat brcstat;
if (brc_buf != NULL)
return;
brc_size = 0;
setuserfile(brcfile, fn_brc);
if ((fd = open(brcfile, O_RDONLY)) == -1)
{
read_brc2();
return;
}
fstat(fd, &brcstat);
brc_get_buf(brcstat.st_size);
brc_size = read(fd, brc_buf, brc_alloc);
close(fd);
}
/* release allocated memory
*
* Do not destory brc_currbid, brc_num, brc_list.
*/
void
brc_release()
{
if (brc_buf) {
free(brc_buf);
brc_buf = NULL;
}
brc_changed = 0;
brc_size = brc_alloc = 0;
}
void
brc_finalize(){
char brcfile[STRLEN];
char tmpfile[STRLEN];
if(!brc_initialized)
return;
brc_update();
setuserfile(brcfile, fn_brc);
snprintf(tmpfile, sizeof(tmpfile), "%s.tmp.%x", brcfile, getpid());
if (brc_buf != NULL) {
int fd = open(tmpfile, O_WRONLY | O_CREAT | O_TRUNC, 0644);
if (fd != -1) {
int ok=0;
if(write(fd, brc_buf, brc_size)==brc_size)
ok=1;
close(fd);
if(ok)
Rename(tmpfile, brcfile);
else
unlink(tmpfile);
}
}
brc_release();
brc_initialized = 0;
}
int
brc_initialize(){
if (brc_initialized)
return 1;
brc_initialized = 1;
brc_expire_time = login_start_time - 365 * 86400;
read_brc_buf();
return 0;
}
/**
* get the read records for bid
*
* @param bid
* @param[out] num number of record for \a bid. 1 <= \a num <= \a BRC_MAXNUM
* \a num = 1 if no records.
* @param[out] list the list of records, length \a num
*
* @return number of read record, 0 if no records
*/
static int
brc_read_record(int bid, int *num, brc_rec *list){
char *ptr;
brcnbrd_t tnum;
ptr = brc_findrecord_in(brc_buf, brc_buf + brc_size, bid, &tnum);
*num = tnum;
if ( ptr ){
assert(0 <= *num && *num <= BRC_MAXNUM);
memcpy(list, ptr + sizeof(brcbid_t) + sizeof(brcnbrd_t),
*num * sizeof(brc_rec));
return *num;
}
list[0].create = *num = 1;
return 0;
}
/**
* @return number of records in \a boardname
*/
int
brc_initial_board(const char *boardname)
{
brc_initialize();
if (strcmp(currboard, boardname) == 0) {
assert(currbid == brc_currbid);
return brc_num;
}
brc_update(); /* write back first */
currbid = getbnum(boardname);
if( currbid == 0 )
currbid = getbnum(DEFAULT_BOARD);
assert(0<=currbid-1 && currbid-1<MAX_BOARD);
brc_currbid = currbid;
currboard = bcache[currbid - 1].brdname;
currbrdattr = bcache[currbid - 1].brdattr;
return brc_read_record(brc_currbid, &brc_num, brc_list);
}
static void
brc_trunc(int bid, time4_t ftime){
brc_rec r;
r.create = ftime;
r.modified = ftime;
brc_insert_record(bid, 1, &r);
if ( bid == brc_currbid ){
brc_num = 1;
brc_list[0] = r;
brc_changed = 0;
}
}
void
brc_toggle_all_read(int bid, int is_all_read)
{
brc_initialize();
if (is_all_read)
brc_trunc(bid, now);
else
brc_trunc(bid, 1);
}
void
brc_addlist(const char *fname, time4_t modified)
{
int n, i;
brc_rec frec;
assert(currbid == brc_currbid);
if (!cuser.userlevel)
return;
brc_initialize();
frec.create = atoi(&fname[2]);
frec.modified = modified;
if (frec.create <= brc_expire_time /* too old, don't do any thing */
/* || fname[0] != 'M' || fname[1] != '.' */ ) {
return;
}
if (brc_num <= 0) { /* uninitialized */
brc_list[0] = frec;
brc_num = 1;
brc_changed = 1;
return;
}
if ((brc_num == 1) && (frec.create < brc_list[0].create)) /* most when after 'v' */
return;
for (n = 0; n < brc_num; n++) { /* using linear search */
if (frec.create == brc_list[n].create) {
if (brc_list[n].modified < modified)
{
brc_list[n].modified = modified;
brc_changed = 1;
}
return;
} else if (frec.create > brc_list[n].create) {
if (brc_num < BRC_MAXNUM)
brc_num++;
/* insert frec into brc_list */
for (i = brc_num - 1; --i >= n; brc_list[i + 1] = brc_list[i]);
brc_list[n] = frec;
brc_changed = 1;
return;
}
}
}
// return:
// 0 - read
// 1 - unread (by create)
// 2 - unread (by modified)
int
brc_unread_time(int bid, time4_t ftime, time4_t modified)
{
int i;
int bnum;
const brc_rec *blist;
brc_initialize();
if (ftime <= brc_expire_time) /* too old */
return 0;
if (brc_currbid && bid == brc_currbid) {
blist = brc_list;
bnum = brc_num;
} else {
blist = brc_find_record(bid, &bnum);
}
if (bnum <= 0)
return 1;
for (i = 0; i < bnum; i++) { /* using linear search */
if (ftime > blist[i].create)
return 1;
else if (ftime == blist[i].create)
{
time4_t brcm = blist[i].modified;
if (modified == 0 || brcm == 0)
return 0;
// bad case... seems like that someone is making -1.
if (modified == (time4_t)-1 || brcm == (time4_t)-1)
return 0;
return modified > brcm ? 2 : 0;
}
}
return 0;
}
int
brc_unread(int bid, const char *fname, time4_t modified)
{
int ftime;
ftime = atoi(&fname[2]); /* this will get the time of the file created */
return brc_unread_time(bid, ftime, modified);
}