ref: 43bfd7255c75836a4956c698fc28e378135867bc
dir: /memfile.c/
/* vi:set ts=8 sts=4 sw=4:
*
* VIM - Vi IMproved by Bram Moolenaar
*
* Do ":help uganda" in Vim to read copying and usage conditions.
* Do ":help credits" in Vim to see a list of people who contributed.
* See README.txt for an overview of the Vim source code.
*/
/*
* memfile.c: Contains the functions for handling blocks of memory which can
* be stored in a file. This is the implementation of a sort of virtual memory.
*
* A memfile consists of a sequence of blocks. The blocks numbered from 0
* upwards have been assigned a place in the actual file. The block number
* is equal to the page number in the file. The
* blocks with negative numbers are currently in memory only. They can be
* assigned a place in the file when too much memory is being used. At that
* moment they get a new, positive, number. A list is used for translation of
* negative to positive numbers.
*
* The size of a block is a multiple of a page size, normally the page size of
* the device the file is on. Most blocks are 1 page long. A Block of multiple
* pages is used for a line that does not fit in a single page.
*
* Each block can be in memory and/or in a file. The block stays in memory
* as long as it is locked. If it is no longer locked it can be swapped out to
* the file. It is only written to the file if it has been changed.
*
* Under normal operation the file is created when opening the memory file and
* deleted when closing the memory file. Only with recovery an existing memory
* file is opened.
*/
#if defined MSDOS || defined(WIN32) || defined(_WIN64)
# include "vimio.h" /* for lseek(), must be before vim.h */
#endif
#include "vim.h"
#ifdef HAVE_FCNTL_H
# include <fcntl.h>
#endif
/*
* Some systems have the page size in statfs.f_bsize, some in stat.st_blksize
*/
#ifdef HAVE_ST_BLKSIZE
# define STATFS stat
# define F_BSIZE st_blksize
# define fstatfs(fd, buf, len, nul) mch_fstat((fd), (buf))
#else
# ifdef HAVE_SYS_STATFS_H
# include <sys/statfs.h>
# define STATFS statfs
# define F_BSIZE f_bsize
# ifdef __MINT__ /* do we still need this? */
# define fstatfs(fd, buf, len, nul) mch_fstat((fd), (buf))
# endif
# endif
#endif
/*
* for Amiga Dos 2.0x we use Flush
*/
#ifdef AMIGA
# ifdef FEAT_ARP
extern int dos2; /* this is in os_amiga.c */
# endif
# ifdef SASC
# include <proto/dos.h>
# include <ios1.h> /* for chkufb() */
# endif
#endif
#define MEMFILE_PAGE_SIZE 4096 /* default page size */
static long_u total_mem_used = 0; /* total memory used for memfiles */
static void mf_ins_hash __ARGS((memfile_T *, bhdr_T *));
static void mf_rem_hash __ARGS((memfile_T *, bhdr_T *));
static bhdr_T *mf_find_hash __ARGS((memfile_T *, blocknr_T));
static void mf_ins_used __ARGS((memfile_T *, bhdr_T *));
static void mf_rem_used __ARGS((memfile_T *, bhdr_T *));
static bhdr_T *mf_release __ARGS((memfile_T *, int));
static bhdr_T *mf_alloc_bhdr __ARGS((memfile_T *, int));
static void mf_free_bhdr __ARGS((bhdr_T *));
static void mf_ins_free __ARGS((memfile_T *, bhdr_T *));
static bhdr_T *mf_rem_free __ARGS((memfile_T *));
static int mf_read __ARGS((memfile_T *, bhdr_T *));
static int mf_write __ARGS((memfile_T *, bhdr_T *));
static int mf_trans_add __ARGS((memfile_T *, bhdr_T *));
static void mf_do_open __ARGS((memfile_T *, char_u *, int));
/*
* The functions for using a memfile:
*
* mf_open() open a new or existing memfile
* mf_open_file() open a swap file for an existing memfile
* mf_close() close (and delete) a memfile
* mf_new() create a new block in a memfile and lock it
* mf_get() get an existing block and lock it
* mf_put() unlock a block, may be marked for writing
* mf_free() remove a block
* mf_sync() sync changed parts of memfile to disk
* mf_release_all() release as much memory as possible
* mf_trans_del() may translate negative to positive block number
* mf_fullname() make file name full path (use before first :cd)
*/
/*
* Open an existing or new memory block file.
*
* fname: name of file to use (NULL means no file at all)
* Note: fname must have been allocated, it is not copied!
* If opening the file fails, fname is freed.
* flags: flags for open() call
*
* If fname != NULL and file cannot be opened, fail.
*
* return value: identifier for this memory block file.
*/
memfile_T *
mf_open(fname, flags)
char_u *fname;
int flags;
{
memfile_T *mfp;
int i;
off_t size;
#if defined(STATFS) && defined(UNIX) && !defined(__QNX__)
# define USE_FSTATFS
struct STATFS stf;
#endif
if ((mfp = (memfile_T *)alloc((unsigned)sizeof(memfile_T))) == NULL)
return NULL;
if (fname == NULL) /* no file for this memfile, use memory only */
{
mfp->mf_fname = NULL;
mfp->mf_ffname = NULL;
mfp->mf_fd = -1;
}
else
{
mf_do_open(mfp, fname, flags); /* try to open the file */
/* if the file cannot be opened, return here */
if (mfp->mf_fd < 0)
{
vim_free(mfp);
return NULL;
}
}
mfp->mf_free_first = NULL; /* free list is empty */
mfp->mf_used_first = NULL; /* used list is empty */
mfp->mf_used_last = NULL;
mfp->mf_dirty = FALSE;
mfp->mf_used_count = 0;
for (i = 0; i < MEMHASHSIZE; ++i)
{
mfp->mf_hash[i] = NULL; /* hash lists are empty */
mfp->mf_trans[i] = NULL; /* trans lists are empty */
}
mfp->mf_page_size = MEMFILE_PAGE_SIZE;
#ifdef USE_FSTATFS
/*
* Try to set the page size equal to the block size of the device.
* Speeds up I/O a lot.
* When recovering, the actual block size will be retrieved from block 0
* in ml_recover(). The size used here may be wrong, therefore
* mf_blocknr_max must be rounded up.
*/
if (mfp->mf_fd >= 0
&& fstatfs(mfp->mf_fd, &stf, sizeof(struct statfs), 0) == 0
&& stf.F_BSIZE >= MIN_SWAP_PAGE_SIZE
&& stf.F_BSIZE <= MAX_SWAP_PAGE_SIZE)
mfp->mf_page_size = stf.F_BSIZE;
#endif
if (mfp->mf_fd < 0 || (flags & (O_TRUNC|O_EXCL))
|| (size = lseek(mfp->mf_fd, (off_t)0L, SEEK_END)) <= 0)
mfp->mf_blocknr_max = 0; /* no file or empty file */
else
mfp->mf_blocknr_max = (blocknr_T)((size + mfp->mf_page_size - 1)
/ mfp->mf_page_size);
mfp->mf_blocknr_min = -1;
mfp->mf_neg_count = 0;
mfp->mf_infile_count = mfp->mf_blocknr_max;
/*
* Compute maximum number of pages ('maxmem' is in Kbyte):
* 'mammem' * 1Kbyte / page-size-in-bytes.
* Avoid overflow by first reducing page size as much as possible.
*/
{
int shift = 10;
unsigned page_size = mfp->mf_page_size;
while (shift > 0 && (page_size & 1) == 0)
{
page_size = page_size >> 1;
--shift;
}
mfp->mf_used_count_max = (p_mm << shift) / page_size;
if (mfp->mf_used_count_max < 10)
mfp->mf_used_count_max = 10;
}
return mfp;
}
/*
* Open a file for an existing memfile. Used when updatecount set from 0 to
* some value.
* If the file already exists, this fails.
* "fname" is the name of file to use (NULL means no file at all)
* Note: "fname" must have been allocated, it is not copied! If opening the
* file fails, "fname" is freed.
*
* return value: FAIL if file could not be opened, OK otherwise
*/
int
mf_open_file(mfp, fname)
memfile_T *mfp;
char_u *fname;
{
mf_do_open(mfp, fname, O_RDWR|O_CREAT|O_EXCL); /* try to open the file */
if (mfp->mf_fd < 0)
return FAIL;
mfp->mf_dirty = TRUE;
return OK;
}
/*
* close a memory file and delete the associated file if 'del_file' is TRUE
*/
void
mf_close(mfp, del_file)
memfile_T *mfp;
int del_file;
{
bhdr_T *hp, *nextp;
NR_TRANS *tp, *tpnext;
int i;
if (mfp == NULL) /* safety check */
return;
if (mfp->mf_fd >= 0)
{
if (close(mfp->mf_fd) < 0)
EMSG(_(e_swapclose));
}
if (del_file && mfp->mf_fname != NULL)
mch_remove(mfp->mf_fname);
/* free entries in used list */
for (hp = mfp->mf_used_first; hp != NULL; hp = nextp)
{
total_mem_used -= hp->bh_page_count * mfp->mf_page_size;
nextp = hp->bh_next;
mf_free_bhdr(hp);
}
while (mfp->mf_free_first != NULL) /* free entries in free list */
vim_free(mf_rem_free(mfp));
for (i = 0; i < MEMHASHSIZE; ++i) /* free entries in trans lists */
for (tp = mfp->mf_trans[i]; tp != NULL; tp = tpnext)
{
tpnext = tp->nt_next;
vim_free(tp);
}
vim_free(mfp->mf_fname);
vim_free(mfp->mf_ffname);
vim_free(mfp);
}
/*
* Close the swap file for a memfile. Used when 'swapfile' is reset.
*/
void
mf_close_file(buf, getlines)
buf_T *buf;
int getlines; /* get all lines into memory? */
{
memfile_T *mfp;
linenr_T lnum;
mfp = buf->b_ml.ml_mfp;
if (mfp == NULL || mfp->mf_fd < 0) /* nothing to close */
return;
if (getlines)
{
/* get all blocks in memory by accessing all lines (clumsy!) */
mf_dont_release = TRUE;
for (lnum = 1; lnum <= buf->b_ml.ml_line_count; ++lnum)
(void)ml_get_buf(buf, lnum, FALSE);
mf_dont_release = FALSE;
/* TODO: should check if all blocks are really in core */
}
if (close(mfp->mf_fd) < 0) /* close the file */
EMSG(_(e_swapclose));
mfp->mf_fd = -1;
if (mfp->mf_fname != NULL)
{
mch_remove(mfp->mf_fname); /* delete the swap file */
vim_free(mfp->mf_fname);
vim_free(mfp->mf_ffname);
mfp->mf_fname = NULL;
mfp->mf_ffname = NULL;
}
}
/*
* Set new size for a memfile. Used when block 0 of a swapfile has been read
* and the size it indicates differs from what was guessed.
*/
void
mf_new_page_size(mfp, new_size)
memfile_T *mfp;
unsigned new_size;
{
/* Correct the memory used for block 0 to the new size, because it will be
* freed with that size later on. */
total_mem_used += new_size - mfp->mf_page_size;
mfp->mf_page_size = new_size;
}
/*
* get a new block
*
* negative: TRUE if negative block number desired (data block)
*/
bhdr_T *
mf_new(mfp, negative, page_count)
memfile_T *mfp;
int negative;
int page_count;
{
bhdr_T *hp; /* new bhdr_T */
bhdr_T *freep; /* first block in free list */
char_u *p;
/*
* If we reached the maximum size for the used memory blocks, release one
* If a bhdr_T is returned, use it and adjust the page_count if necessary.
*/
hp = mf_release(mfp, page_count);
/*
* Decide on the number to use:
* If there is a free block, use its number.
* Otherwise use mf_block_min for a negative number, mf_block_max for
* a positive number.
*/
freep = mfp->mf_free_first;
if (!negative && freep != NULL && freep->bh_page_count >= page_count)
{
/*
* If the block in the free list has more pages, take only the number
* of pages needed and allocate a new bhdr_T with data
*
* If the number of pages matches and mf_release() did not return a
* bhdr_T, use the bhdr_T from the free list and allocate the data
*
* If the number of pages matches and mf_release() returned a bhdr_T,
* just use the number and free the bhdr_T from the free list
*/
if (freep->bh_page_count > page_count)
{
if (hp == NULL && (hp = mf_alloc_bhdr(mfp, page_count)) == NULL)
return NULL;
hp->bh_bnum = freep->bh_bnum;
freep->bh_bnum += page_count;
freep->bh_page_count -= page_count;
}
else if (hp == NULL) /* need to allocate memory for this block */
{
if ((p = (char_u *)alloc(mfp->mf_page_size * page_count)) == NULL)
return NULL;
hp = mf_rem_free(mfp);
hp->bh_data = p;
}
else /* use the number, remove entry from free list */
{
freep = mf_rem_free(mfp);
hp->bh_bnum = freep->bh_bnum;
vim_free(freep);
}
}
else /* get a new number */
{
if (hp == NULL && (hp = mf_alloc_bhdr(mfp, page_count)) == NULL)
return NULL;
if (negative)
{
hp->bh_bnum = mfp->mf_blocknr_min--;
mfp->mf_neg_count++;
}
else
{
hp->bh_bnum = mfp->mf_blocknr_max;
mfp->mf_blocknr_max += page_count;
}
}
hp->bh_flags = BH_LOCKED | BH_DIRTY; /* new block is always dirty */
mfp->mf_dirty = TRUE;
hp->bh_page_count = page_count;
mf_ins_used(mfp, hp);
mf_ins_hash(mfp, hp);
/*
* Init the data to all zero, to avoid reading uninitialized data.
* This also avoids that the passwd file ends up in the swap file!
*/
(void)vim_memset((char *)(hp->bh_data), 0, (size_t)mfp->mf_page_size);
return hp;
}
/*
* get existing block 'nr' with 'page_count' pages
*
* Note: The caller should first check a negative nr with mf_trans_del()
*/
bhdr_T *
mf_get(mfp, nr, page_count)
memfile_T *mfp;
blocknr_T nr;
int page_count;
{
bhdr_T *hp;
/* doesn't exist */
if (nr >= mfp->mf_blocknr_max || nr <= mfp->mf_blocknr_min)
return NULL;
/*
* see if it is in the cache
*/
hp = mf_find_hash(mfp, nr);
if (hp == NULL) /* not in the hash list */
{
if (nr < 0 || nr >= mfp->mf_infile_count) /* can't be in the file */
return NULL;
/* could check here if the block is in the free list */
/*
* Check if we need to flush an existing block.
* If so, use that block.
* If not, allocate a new block.
*/
hp = mf_release(mfp, page_count);
if (hp == NULL && (hp = mf_alloc_bhdr(mfp, page_count)) == NULL)
return NULL;
hp->bh_bnum = nr;
hp->bh_flags = 0;
hp->bh_page_count = page_count;
if (mf_read(mfp, hp) == FAIL) /* cannot read the block! */
{
mf_free_bhdr(hp);
return NULL;
}
}
else
{
mf_rem_used(mfp, hp); /* remove from list, insert in front below */
mf_rem_hash(mfp, hp);
}
hp->bh_flags |= BH_LOCKED;
mf_ins_used(mfp, hp); /* put in front of used list */
mf_ins_hash(mfp, hp); /* put in front of hash list */
return hp;
}
/*
* release the block *hp
*
* dirty: Block must be written to file later
* infile: Block should be in file (needed for recovery)
*
* no return value, function cannot fail
*/
void
mf_put(mfp, hp, dirty, infile)
memfile_T *mfp;
bhdr_T *hp;
int dirty;
int infile;
{
int flags;
flags = hp->bh_flags;
if ((flags & BH_LOCKED) == 0)
EMSG(_("E293: block was not locked"));
flags &= ~BH_LOCKED;
if (dirty)
{
flags |= BH_DIRTY;
mfp->mf_dirty = TRUE;
}
hp->bh_flags = flags;
if (infile)
mf_trans_add(mfp, hp); /* may translate negative in positive nr */
}
/*
* block *hp is no longer in used, may put it in the free list of memfile *mfp
*/
void
mf_free(mfp, hp)
memfile_T *mfp;
bhdr_T *hp;
{
vim_free(hp->bh_data); /* free the memory */
mf_rem_hash(mfp, hp); /* get *hp out of the hash list */
mf_rem_used(mfp, hp); /* get *hp out of the used list */
if (hp->bh_bnum < 0)
{
vim_free(hp); /* don't want negative numbers in free list */
mfp->mf_neg_count--;
}
else
mf_ins_free(mfp, hp); /* put *hp in the free list */
}
#if defined(__MORPHOS__) && defined(__libnix__)
/* function is missing in MorphOS libnix version */
extern unsigned long *__stdfiledes;
static unsigned long
fdtofh(int filedescriptor)
{
return __stdfiledes[filedescriptor];
}
#endif
/*
* Sync the memory file *mfp to disk.
* Flags:
* MFS_ALL If not given, blocks with negative numbers are not synced,
* even when they are dirty!
* MFS_STOP Stop syncing when a character becomes available, but sync at
* least one block.
* MFS_FLUSH Make sure buffers are flushed to disk, so they will survive a
* system crash.
* MFS_ZERO Only write block 0.
*
* Return FAIL for failure, OK otherwise
*/
int
mf_sync(mfp, flags)
memfile_T *mfp;
int flags;
{
int status;
bhdr_T *hp;
#if defined(SYNC_DUP_CLOSE) && !defined(MSDOS)
int fd;
#endif
int got_int_save = got_int;
if (mfp->mf_fd < 0) /* there is no file, nothing to do */
{
mfp->mf_dirty = FALSE;
return FAIL;
}
/* Only a CTRL-C while writing will break us here, not one typed
* previously. */
got_int = FALSE;
/*
* sync from last to first (may reduce the probability of an inconsistent
* file) If a write fails, it is very likely caused by a full filesystem.
* Then we only try to write blocks within the existing file. If that also
* fails then we give up.
*/
status = OK;
for (hp = mfp->mf_used_last; hp != NULL; hp = hp->bh_prev)
if (((flags & MFS_ALL) || hp->bh_bnum >= 0)
&& (hp->bh_flags & BH_DIRTY)
&& (status == OK || (hp->bh_bnum >= 0
&& hp->bh_bnum < mfp->mf_infile_count)))
{
if ((flags & MFS_ZERO) && hp->bh_bnum != 0)
continue;
if (mf_write(mfp, hp) == FAIL)
{
if (status == FAIL) /* double error: quit syncing */
break;
status = FAIL;
}
if (flags & MFS_STOP)
{
/* Stop when char available now. */
if (ui_char_avail())
break;
}
else
ui_breakcheck();
if (got_int)
break;
}
/*
* If the whole list is flushed, the memfile is not dirty anymore.
* In case of an error this flag is also set, to avoid trying all the time.
*/
if (hp == NULL || status == FAIL)
mfp->mf_dirty = FALSE;
if ((flags & MFS_FLUSH) && *p_sws != NUL)
{
#if defined(UNIX)
# ifdef HAVE_FSYNC
/*
* most Unixes have the very useful fsync() function, just what we need.
* However, with OS/2 and EMX it is also available, but there are
* reports of bad problems with it (a bug in HPFS.IFS).
* So we disable use of it here in case someone tries to be smart
* and changes os_os2_cfg.h... (even though there is no __EMX__ test
* in the #if, as __EMX__ does not have sync(); we hope for a timely
* sync from the system itself).
*/
# if defined(__EMX__)
error "Dont use fsync with EMX! Read emxdoc.doc or emxfix01.doc for info."
# endif
if (STRCMP(p_sws, "fsync") == 0)
{
if (fsync(mfp->mf_fd))
status = FAIL;
}
else
# endif
/* OpenNT is strictly POSIX (Benzinger) */
/* Tandem/Himalaya NSK-OSS doesn't have sync() */
# if defined(__OPENNT) || defined(__TANDEM)
fflush(NULL);
# else
sync();
# endif
#endif
#ifdef VMS
if (STRCMP(p_sws, "fsync") == 0)
{
if (fsync(mfp->mf_fd))
status = FAIL;
}
#endif
#ifdef MSDOS
if (_dos_commit(mfp->mf_fd))
status = FAIL;
#else
# ifdef SYNC_DUP_CLOSE
/*
* Win32 is a bit more work: Duplicate the file handle and close it.
* This should flush the file to disk.
*/
if ((fd = dup(mfp->mf_fd)) >= 0)
close(fd);
# endif
#endif
#ifdef AMIGA
# if defined(__AROS__) || defined(__amigaos4__)
if (fsync(mfp->mf_fd) != 0)
status = FAIL;
# else
/*
* Flush() only exists for AmigaDos 2.0.
* For 1.3 it should be done with close() + open(), but then the risk
* is that the open() may fail and lose the file....
*/
# ifdef FEAT_ARP
if (dos2)
# endif
# ifdef SASC
{
struct UFB *fp = chkufb(mfp->mf_fd);
if (fp != NULL)
Flush(fp->ufbfh);
}
# else
# if defined(_DCC) || defined(__GNUC__) || defined(__MORPHOS__)
{
# if defined(__GNUC__) && !defined(__MORPHOS__) && defined(__libnix__)
/* Have function (in libnix at least),
* but ain't got no prototype anywhere. */
extern unsigned long fdtofh(int filedescriptor);
# endif
# if !defined(__libnix__)
fflush(NULL);
# else
BPTR fh = (BPTR)fdtofh(mfp->mf_fd);
if (fh != 0)
Flush(fh);
# endif
}
# else /* assume Manx */
Flush(_devtab[mfp->mf_fd].fd);
# endif
# endif
# endif
#endif /* AMIGA */
}
got_int |= got_int_save;
return status;
}
/*
* For all blocks in memory file *mfp that have a positive block number set
* the dirty flag. These are blocks that need to be written to a newly
* created swapfile.
*/
void
mf_set_dirty(mfp)
memfile_T *mfp;
{
bhdr_T *hp;
for (hp = mfp->mf_used_last; hp != NULL; hp = hp->bh_prev)
if (hp->bh_bnum > 0)
hp->bh_flags |= BH_DIRTY;
mfp->mf_dirty = TRUE;
}
/*
* insert block *hp in front of hashlist of memfile *mfp
*/
static void
mf_ins_hash(mfp, hp)
memfile_T *mfp;
bhdr_T *hp;
{
bhdr_T *hhp;
int hash;
hash = MEMHASH(hp->bh_bnum);
hhp = mfp->mf_hash[hash];
hp->bh_hash_next = hhp;
hp->bh_hash_prev = NULL;
if (hhp != NULL)
hhp->bh_hash_prev = hp;
mfp->mf_hash[hash] = hp;
}
/*
* remove block *hp from hashlist of memfile list *mfp
*/
static void
mf_rem_hash(mfp, hp)
memfile_T *mfp;
bhdr_T *hp;
{
if (hp->bh_hash_prev == NULL)
mfp->mf_hash[MEMHASH(hp->bh_bnum)] = hp->bh_hash_next;
else
hp->bh_hash_prev->bh_hash_next = hp->bh_hash_next;
if (hp->bh_hash_next)
hp->bh_hash_next->bh_hash_prev = hp->bh_hash_prev;
}
/*
* look in hash lists of memfile *mfp for block header with number 'nr'
*/
static bhdr_T *
mf_find_hash(mfp, nr)
memfile_T *mfp;
blocknr_T nr;
{
bhdr_T *hp;
for (hp = mfp->mf_hash[MEMHASH(nr)]; hp != NULL; hp = hp->bh_hash_next)
if (hp->bh_bnum == nr)
break;
return hp;
}
/*
* insert block *hp in front of used list of memfile *mfp
*/
static void
mf_ins_used(mfp, hp)
memfile_T *mfp;
bhdr_T *hp;
{
hp->bh_next = mfp->mf_used_first;
mfp->mf_used_first = hp;
hp->bh_prev = NULL;
if (hp->bh_next == NULL) /* list was empty, adjust last pointer */
mfp->mf_used_last = hp;
else
hp->bh_next->bh_prev = hp;
mfp->mf_used_count += hp->bh_page_count;
total_mem_used += hp->bh_page_count * mfp->mf_page_size;
}
/*
* remove block *hp from used list of memfile *mfp
*/
static void
mf_rem_used(mfp, hp)
memfile_T *mfp;
bhdr_T *hp;
{
if (hp->bh_next == NULL) /* last block in used list */
mfp->mf_used_last = hp->bh_prev;
else
hp->bh_next->bh_prev = hp->bh_prev;
if (hp->bh_prev == NULL) /* first block in used list */
mfp->mf_used_first = hp->bh_next;
else
hp->bh_prev->bh_next = hp->bh_next;
mfp->mf_used_count -= hp->bh_page_count;
total_mem_used -= hp->bh_page_count * mfp->mf_page_size;
}
/*
* Release the least recently used block from the used list if the number
* of used memory blocks gets to big.
*
* Return the block header to the caller, including the memory block, so
* it can be re-used. Make sure the page_count is right.
*/
static bhdr_T *
mf_release(mfp, page_count)
memfile_T *mfp;
int page_count;
{
bhdr_T *hp;
int need_release;
buf_T *buf;
/* don't release while in mf_close_file() */
if (mf_dont_release)
return NULL;
/*
* Need to release a block if the number of blocks for this memfile is
* higher than the maximum or total memory used is over 'maxmemtot'
*/
need_release = ((mfp->mf_used_count >= mfp->mf_used_count_max)
|| (total_mem_used >> 10) >= (long_u)p_mmt);
/*
* Try to create a swap file if the amount of memory used is getting too
* high.
*/
if (mfp->mf_fd < 0 && need_release && p_uc)
{
/* find for which buffer this memfile is */
for (buf = firstbuf; buf != NULL; buf = buf->b_next)
if (buf->b_ml.ml_mfp == mfp)
break;
if (buf != NULL && buf->b_may_swap)
ml_open_file(buf);
}
/*
* don't release a block if
* there is no file for this memfile
* or
* the number of blocks for this memfile is lower than the maximum
* and
* total memory used is not up to 'maxmemtot'
*/
if (mfp->mf_fd < 0 || !need_release)
return NULL;
for (hp = mfp->mf_used_last; hp != NULL; hp = hp->bh_prev)
if (!(hp->bh_flags & BH_LOCKED))
break;
if (hp == NULL) /* not a single one that can be released */
return NULL;
/*
* If the block is dirty, write it.
* If the write fails we don't free it.
*/
if ((hp->bh_flags & BH_DIRTY) && mf_write(mfp, hp) == FAIL)
return NULL;
mf_rem_used(mfp, hp);
mf_rem_hash(mfp, hp);
/*
* If a bhdr_T is returned, make sure that the page_count of bh_data is
* right
*/
if (hp->bh_page_count != page_count)
{
vim_free(hp->bh_data);
if ((hp->bh_data = alloc(mfp->mf_page_size * page_count)) == NULL)
{
vim_free(hp);
return NULL;
}
hp->bh_page_count = page_count;
}
return hp;
}
/*
* release as many blocks as possible
* Used in case of out of memory
*
* return TRUE if any memory was released
*/
int
mf_release_all()
{
buf_T *buf;
memfile_T *mfp;
bhdr_T *hp;
int retval = FALSE;
for (buf = firstbuf; buf != NULL; buf = buf->b_next)
{
mfp = buf->b_ml.ml_mfp;
if (mfp != NULL)
{
/* If no swap file yet, may open one */
if (mfp->mf_fd < 0 && buf->b_may_swap)
ml_open_file(buf);
/* only if there is a swapfile */
if (mfp->mf_fd >= 0)
{
for (hp = mfp->mf_used_last; hp != NULL; )
{
if (!(hp->bh_flags & BH_LOCKED)
&& (!(hp->bh_flags & BH_DIRTY)
|| mf_write(mfp, hp) != FAIL))
{
mf_rem_used(mfp, hp);
mf_rem_hash(mfp, hp);
mf_free_bhdr(hp);
hp = mfp->mf_used_last; /* re-start, list was changed */
retval = TRUE;
}
else
hp = hp->bh_prev;
}
}
}
}
return retval;
}
/*
* Allocate a block header and a block of memory for it
*/
static bhdr_T *
mf_alloc_bhdr(mfp, page_count)
memfile_T *mfp;
int page_count;
{
bhdr_T *hp;
if ((hp = (bhdr_T *)alloc((unsigned)sizeof(bhdr_T))) != NULL)
{
if ((hp->bh_data = (char_u *)alloc(mfp->mf_page_size * page_count))
== NULL)
{
vim_free(hp); /* not enough memory */
return NULL;
}
hp->bh_page_count = page_count;
}
return hp;
}
/*
* Free a block header and the block of memory for it
*/
static void
mf_free_bhdr(hp)
bhdr_T *hp;
{
vim_free(hp->bh_data);
vim_free(hp);
}
/*
* insert entry *hp in the free list
*/
static void
mf_ins_free(mfp, hp)
memfile_T *mfp;
bhdr_T *hp;
{
hp->bh_next = mfp->mf_free_first;
mfp->mf_free_first = hp;
}
/*
* remove the first entry from the free list and return a pointer to it
* Note: caller must check that mfp->mf_free_first is not NULL!
*/
static bhdr_T *
mf_rem_free(mfp)
memfile_T *mfp;
{
bhdr_T *hp;
hp = mfp->mf_free_first;
mfp->mf_free_first = hp->bh_next;
return hp;
}
/*
* read a block from disk
*
* Return FAIL for failure, OK otherwise
*/
static int
mf_read(mfp, hp)
memfile_T *mfp;
bhdr_T *hp;
{
off_t offset;
unsigned page_size;
unsigned size;
if (mfp->mf_fd < 0) /* there is no file, can't read */
return FAIL;
page_size = mfp->mf_page_size;
offset = (off_t)page_size * hp->bh_bnum;
size = page_size * hp->bh_page_count;
if (lseek(mfp->mf_fd, offset, SEEK_SET) != offset)
{
PERROR(_("E294: Seek error in swap file read"));
return FAIL;
}
if ((unsigned)vim_read(mfp->mf_fd, hp->bh_data, size) != size)
{
PERROR(_("E295: Read error in swap file"));
return FAIL;
}
return OK;
}
/*
* write a block to disk
*
* Return FAIL for failure, OK otherwise
*/
static int
mf_write(mfp, hp)
memfile_T *mfp;
bhdr_T *hp;
{
off_t offset; /* offset in the file */
blocknr_T nr; /* block nr which is being written */
bhdr_T *hp2;
unsigned page_size; /* number of bytes in a page */
unsigned page_count; /* number of pages written */
unsigned size; /* number of bytes written */
if (mfp->mf_fd < 0) /* there is no file, can't write */
return FAIL;
if (hp->bh_bnum < 0) /* must assign file block number */
if (mf_trans_add(mfp, hp) == FAIL)
return FAIL;
page_size = mfp->mf_page_size;
/*
* We don't want gaps in the file. Write the blocks in front of *hp
* to extend the file.
* If block 'mf_infile_count' is not in the hash list, it has been
* freed. Fill the space in the file with data from the current block.
*/
for (;;)
{
nr = hp->bh_bnum;
if (nr > mfp->mf_infile_count) /* beyond end of file */
{
nr = mfp->mf_infile_count;
hp2 = mf_find_hash(mfp, nr); /* NULL catched below */
}
else
hp2 = hp;
offset = (off_t)page_size * nr;
if (lseek(mfp->mf_fd, offset, SEEK_SET) != offset)
{
PERROR(_("E296: Seek error in swap file write"));
return FAIL;
}
if (hp2 == NULL) /* freed block, fill with dummy data */
page_count = 1;
else
page_count = hp2->bh_page_count;
size = page_size * page_count;
if ((unsigned)vim_write(mfp->mf_fd,
(hp2 == NULL ? hp : hp2)->bh_data, size) != size)
{
/*
* Avoid repeating the error message, this mostly happens when the
* disk is full. We give the message again only after a successful
* write or when hitting a key. We keep on trying, in case some
* space becomes available.
*/
if (!did_swapwrite_msg)
EMSG(_("E297: Write error in swap file"));
did_swapwrite_msg = TRUE;
return FAIL;
}
did_swapwrite_msg = FALSE;
if (hp2 != NULL) /* written a non-dummy block */
hp2->bh_flags &= ~BH_DIRTY;
/* appended to the file */
if (nr + (blocknr_T)page_count > mfp->mf_infile_count)
mfp->mf_infile_count = nr + page_count;
if (nr == hp->bh_bnum) /* written the desired block */
break;
}
return OK;
}
/*
* Make block number for *hp positive and add it to the translation list
*
* Return FAIL for failure, OK otherwise
*/
static int
mf_trans_add(mfp, hp)
memfile_T *mfp;
bhdr_T *hp;
{
bhdr_T *freep;
blocknr_T new_bnum;
int hash;
NR_TRANS *np;
int page_count;
if (hp->bh_bnum >= 0) /* it's already positive */
return OK;
if ((np = (NR_TRANS *)alloc((unsigned)sizeof(NR_TRANS))) == NULL)
return FAIL;
/*
* get a new number for the block.
* If the first item in the free list has sufficient pages, use its number
* Otherwise use mf_blocknr_max.
*/
freep = mfp->mf_free_first;
page_count = hp->bh_page_count;
if (freep != NULL && freep->bh_page_count >= page_count)
{
new_bnum = freep->bh_bnum;
/*
* If the page count of the free block was larger, recude it.
* If the page count matches, remove the block from the free list
*/
if (freep->bh_page_count > page_count)
{
freep->bh_bnum += page_count;
freep->bh_page_count -= page_count;
}
else
{
freep = mf_rem_free(mfp);
vim_free(freep);
}
}
else
{
new_bnum = mfp->mf_blocknr_max;
mfp->mf_blocknr_max += page_count;
}
np->nt_old_bnum = hp->bh_bnum; /* adjust number */
np->nt_new_bnum = new_bnum;
mf_rem_hash(mfp, hp); /* remove from old hash list */
hp->bh_bnum = new_bnum;
mf_ins_hash(mfp, hp); /* insert in new hash list */
hash = MEMHASH(np->nt_old_bnum); /* insert in trans list */
np->nt_next = mfp->mf_trans[hash];
mfp->mf_trans[hash] = np;
if (np->nt_next != NULL)
np->nt_next->nt_prev = np;
np->nt_prev = NULL;
return OK;
}
/*
* Lookup a translation from the trans lists and delete the entry
*
* Return the positive new number when found, the old number when not found
*/
blocknr_T
mf_trans_del(mfp, old_nr)
memfile_T *mfp;
blocknr_T old_nr;
{
int hash;
NR_TRANS *np;
blocknr_T new_bnum;
hash = MEMHASH(old_nr);
for (np = mfp->mf_trans[hash]; np != NULL; np = np->nt_next)
if (np->nt_old_bnum == old_nr)
break;
if (np == NULL) /* not found */
return old_nr;
mfp->mf_neg_count--;
new_bnum = np->nt_new_bnum;
if (np->nt_prev != NULL) /* remove entry from the trans list */
np->nt_prev->nt_next = np->nt_next;
else
mfp->mf_trans[hash] = np->nt_next;
if (np->nt_next != NULL)
np->nt_next->nt_prev = np->nt_prev;
vim_free(np);
return new_bnum;
}
/*
* Set mfp->mf_ffname according to mfp->mf_fname and some other things.
* Only called when creating or renaming the swapfile. Either way it's a new
* name so we must work out the full path name.
*/
void
mf_set_ffname(mfp)
memfile_T *mfp;
{
mfp->mf_ffname = FullName_save(mfp->mf_fname, FALSE);
}
/*
* Make the name of the file used for the memfile a full path.
* Used before doing a :cd
*/
void
mf_fullname(mfp)
memfile_T *mfp;
{
if (mfp != NULL && mfp->mf_fname != NULL && mfp->mf_ffname != NULL)
{
vim_free(mfp->mf_fname);
mfp->mf_fname = mfp->mf_ffname;
mfp->mf_ffname = NULL;
}
}
/*
* return TRUE if there are any translations pending for 'mfp'
*/
int
mf_need_trans(mfp)
memfile_T *mfp;
{
return (mfp->mf_fname != NULL && mfp->mf_neg_count > 0);
}
/*
* Open a swap file for a memfile.
* The "fname" must be in allocated memory, and is consumed (also when an
* error occurs).
*/
static void
mf_do_open(mfp, fname, flags)
memfile_T *mfp;
char_u *fname;
int flags; /* flags for open() */
{
#ifdef HAVE_LSTAT
struct stat sb;
#endif
mfp->mf_fname = fname;
/*
* Get the full path name before the open, because this is
* not possible after the open on the Amiga.
* fname cannot be NameBuff, because it must have been allocated.
*/
mf_set_ffname(mfp);
#if defined(MSDOS) || defined(MSWIN) || defined(RISCOS)
/*
* A ":!cd e:xxx" may change the directory without us knowning, use the
* full pathname always. Careful: This frees fname!
*/
mf_fullname(mfp);
#endif
#ifdef HAVE_LSTAT
/*
* Extra security check: When creating a swap file it really shouldn't
* exist yet. If there is a symbolic link, this is most likely an attack.
*/
if ((flags & O_CREAT) && mch_lstat((char *)mfp->mf_fname, &sb) >= 0)
{
mfp->mf_fd = -1;
EMSG(_("E300: Swap file already exists (symlink attack?)"));
}
else
#endif
{
/*
* try to open the file
*/
flags |= O_EXTRA | O_NOFOLLOW;
#ifdef WIN32
/* Prevent handle inheritance that cause problems with Cscope
* (swap file may not be deleted if cscope connection was open after
* the file) */
flags |= O_NOINHERIT;
#endif
mfp->mf_fd = mch_open_rw((char *)mfp->mf_fname, flags);
}
/*
* If the file cannot be opened, use memory only
*/
if (mfp->mf_fd < 0)
{
vim_free(mfp->mf_fname);
vim_free(mfp->mf_ffname);
mfp->mf_fname = NULL;
mfp->mf_ffname = NULL;
}
else
mch_hide(mfp->mf_fname); /* try setting the 'hidden' flag */
}