From bea6a16a692d4912b404a085fe4adff73c55e631 Mon Sep 17 00:00:00 2001 From: batt Date: Tue, 16 Sep 2008 12:48:18 +0000 Subject: [PATCH] Remove dead code. git-svn-id: https://src.develer.com/svnoss/bertos/trunk@1810 38d2e660-2303-0410-9eaa-f027e97ec537 --- bertos/fs/battfs.c | 217 --------------------------------------------- 1 file changed, 217 deletions(-) diff --git a/bertos/fs/battfs.c b/bertos/fs/battfs.c index 73e3536a..42331906 100644 --- a/bertos/fs/battfs.c +++ b/bertos/fs/battfs.c @@ -343,223 +343,6 @@ static bool fillPageArray(struct BattFsSuper *disk, pgoff_t *filelen_table) return true; } -#if 0 -/** - * Find the latest version of a page, starting from the - * page supplied by \a page_array. - * The pages are read from the disk until a different - * inode or page offset is found. - * The lastest version of the page is moved in the first - * position of \a page_array. - * \return the number of old versions of the page or PAGE_ERROR - * on disk read errors. - */ -static pgcnt_t findLastVersion(struct BattFsSuper *disk, pgcnt_t *page_array) -{ - pgcnt_t *array_start = page_array; - BattFsPageHeader hdr; - if (!battfs_readHeader(disk, *page_array++, &hdr)) - return PAGE_ERROR; - - /* Free space: early bailout */ - if (hdr.fcs != computeFcs(&hdr)) - return 0; - - /* - * If the first page is valid, - * inode and pg_off in the array are taken - * as the current page markers. - */ - inode_t curr_inode = hdr.inode; - pgoff_t curr_pgoff = hdr.pgoff; - - /* Temps used to find the sequence number range */ - seq_t minl = HALF_SEQ - 1; - seq_t maxl = 0; - seq_t minh = MAX_SEQ; - seq_t maxh = MAX_SEQ; - pgcnt_t lpos = 0, hpos = 0, dup_cnt = 0; - - /* - * Find min and max values for the two - * half of seq_num range. - * With this we can find seqnum wraparounds. - * seq_t is a type that has at least 1 bit more than - * pgaddr_t. So all version of a page blocks can be numbered using - * at most half numbers of a seq_t type. - * The sequence number algorithm increments by 1 the previous seq_num - * every time a page is rewritten. So the sequence is - * guaranteed to be countiguous. - * Only wrap arounds may happen, but due to half size sequence limitation, - * there are only 4 possible situations: - * - * \verbatim - * |------lower half------|-------upper half-------| - * - * 1) |------minl*****maxl---|------------------------| - * 2) |------minl********maxl|minh******maxh----------| - * 3) |----------------------|----minh*******maxh-----| - * 4) |minl******maxl--------|------------minh****maxh| - * \endverbatim - * - * Situations 1 and 3 are easy to detect, while 2 and 4 require more care. - */ - do - { - if (hdr.seq < HALF_SEQ) - { - minl = MIN(minl, hdr.seq); - if (hdr.seq > maxl) - { - maxl = hdr.seq; - lpos = dup_cnt; - } - } - else - { - minh = MIN(minh, hdr.seq); - if (hdr.seq > maxh) - { - maxh = hdr.seq; - hpos = dup_cnt; - } - } - - if (!battfs_readHeader(disk, *page_array++, &hdr)) - return PAGE_ERROR; - dup_cnt++; - } - while (curr_inode == hdr.inode && curr_pgoff == hdr.pgoff && hdr.fcs == computeFcs(&hdr)); - - - /* Return early if there is only one version of the current page */ - if (dup_cnt == 1) - return 0; - - /* Find the position in the array of the last version of the page */ - pgcnt_t last_ver = hpos; - if (maxl >= minl) - { - /* Valid interval found in lower half */ - if (maxh >= minh) - { - /* Valid interval also found in upper half */ - if (maxl != minh - 1) - { - /* Interval starts in upper half and ends in lower */ - ASSERT(minl == 0); - ASSERT(maxh == MAX_SEQ); - - last_ver = lpos; - } - } - else - /* - * Upper interval is invalid. - * Use lower values. - */ - last_ver = lpos; - } - - /* Put last page version at array start position */ - SWAP(array_start[0], array_start[last_ver]); - - return dup_cnt - 1; -} - -/** - * Collect old pages, removing empty spaces from \a pg_array, for a maximum len of \a pg_len. - * Once the collect task is completed, copy \a old_cnt pages from \a old_pages at the - * end of free space in pg_array. - */ -void collectOldPages(pgcnt_t *pg_array, pgcnt_t pg_len, pgcnt_t *old_pages, pgcnt_t old_cnt) -{ - bool copy = false; - pgcnt_t gap = 0; - - for (pgcnt_t curr_page = 0; curr_page < pg_len; curr_page++) - { - if (!copy) - { - if (pg_array[curr_page] == PAGE_UNSET_SENTINEL) - gap++; - else - { - pg_array[curr_page - gap] = pg_array[curr_page]; - copy = true; - } - } - else - { - if (pg_array[curr_page] != PAGE_UNSET_SENTINEL) - pg_array[curr_page - gap] = pg_array[curr_page]; - else - { - gap++; - copy = false; - } - } - } - ASSERT(gap == old_cnt); - pg_array += pg_len - old_cnt; - - memcpy(pg_array, old_pages, old_cnt * sizeof(pgcnt_t)); -} - -/** - * This function scan the page array of \a disk looking for - * old versions of the same page. - * - * Only the last version is kept as valid, the old ones are inserted - * in the free blocks heap. - * \return true if ok, false on disk read errors. - * \note The whole disk is scanned once. - */ -static bool dropOldPages(struct BattFsSuper *disk) -{ - #define OLD_PAGE_BUFLEN 64 - pgcnt_t old_pages[OLD_PAGE_BUFLEN]; - pgcnt_t old_cnt = 0; - - pgcnt_t *curr_page = disk->page_array; - pgcnt_t *collect_start = disk->page_array; - pgcnt_t collect_len = disk->page_count; - pgcnt_t dup_pages; - - do - { - dup_pages = findLastVersion(disk, curr_page); - if (dup_pages == PAGE_ERROR) - return false; - /* The first page is the last version */ - curr_page++; - while (dup_pages--) - { - if (old_cnt >= OLD_PAGE_BUFLEN) - { - collectOldPages(collect_start, collect_len, old_pages, old_cnt); - collect_len -= old_cnt; - disk->free_bytes += old_cnt * (disk->page_size - BATTFS_HEADER_LEN); - disk->free_page_start -= old_cnt; - curr_page -= old_cnt; - collect_start = curr_page; - old_cnt = 0; - } - - old_pages[old_cnt++] = *curr_page; - *curr_page++ = PAGE_UNSET_SENTINEL; - } - } - while (curr_page < disk->page_array + disk->free_page_start); - - collectOldPages(collect_start, collect_len, old_pages, old_cnt); - disk->free_bytes += old_cnt * (disk->page_size - BATTFS_HEADER_LEN); - disk->free_page_start -= old_cnt; - - return true; -} -#endif - /** * Initialize and mount disk described by * \a disk. -- 2.25.1