Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
Fetching contributors…

Cannot retrieve contributors at this time

1571 lines (1421 sloc) 39.516 kb
/* 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.
*/
#include "vim.h"
/*
* 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_write_block __ARGS((memfile_T *mfp, bhdr_T *hp, off_t offset, unsigned size));
static int mf_trans_add __ARGS((memfile_T *, bhdr_T *));
static void mf_do_open __ARGS((memfile_T *, char_u *, int));
static void mf_hash_init __ARGS((mf_hashtab_T *));
static void mf_hash_free __ARGS((mf_hashtab_T *));
static void mf_hash_free_all __ARGS((mf_hashtab_T *));
static mf_hashitem_T *mf_hash_find __ARGS((mf_hashtab_T *, blocknr_T));
static void mf_hash_add_item __ARGS((mf_hashtab_T *, mf_hashitem_T *));
static void mf_hash_rem_item __ARGS((mf_hashtab_T *, mf_hashitem_T *));
static int mf_hash_grow __ARGS((mf_hashtab_T *));
/*
* 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;
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;
mf_hash_init(&mfp->mf_hash);
mf_hash_init(&mfp->mf_trans);
mfp->mf_page_size = MEMFILE_PAGE_SIZE;
#ifdef FEAT_CRYPT
mfp->mf_old_key = NULL;
#endif
#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;
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));
mf_hash_free(&mfp->mf_hash);
mf_hash_free_all(&mfp->mf_trans); /* free hashtable and its items */
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 * page_count);
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;
{
mf_hash_add_item(&mfp->mf_hash, (mf_hashitem_T *)hp);
}
/*
* remove block *hp from hashlist of memfile list *mfp
*/
static void
mf_rem_hash(mfp, hp)
memfile_T *mfp;
bhdr_T *hp;
{
mf_hash_rem_item(&mfp->mf_hash, (mf_hashitem_T *)hp);
}
/*
* 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;
{
return (bhdr_T *)mf_hash_find(&mfp->mf_hash, nr);
}
/*
* 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)read_eintr(mfp->mf_fd, hp->bh_data, size) != size)
{
PERROR(_("E295: Read error in swap file"));
return FAIL;
}
#ifdef FEAT_CRYPT
/* Decrypt if 'key' is set and this is a data block. */
if (*mfp->mf_buffer->b_p_key != NUL)
ml_decrypt_data(mfp, hp->bh_data, offset, size);
#endif
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 (mf_write_block(mfp, hp2 == NULL ? hp : hp2, offset, size) == FAIL)
{
/*
* 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;
}
/*
* Write block "hp" with data size "size" to file "mfp->mf_fd".
* Takes care of encryption.
* Return FAIL or OK.
*/
static int
mf_write_block(mfp, hp, offset, size)
memfile_T *mfp;
bhdr_T *hp;
off_t offset UNUSED;
unsigned size;
{
char_u *data = hp->bh_data;
int result = OK;
#ifdef FEAT_CRYPT
/* Encrypt if 'key' is set and this is a data block. */
if (*mfp->mf_buffer->b_p_key != NUL)
{
data = ml_encrypt_data(mfp, data, offset, size);
if (data == NULL)
return FAIL;
}
#endif
if ((unsigned)write_eintr(mfp->mf_fd, data, size) != size)
result = FAIL;
#ifdef FEAT_CRYPT
if (data != hp->bh_data)
vim_free(data);
#endif
return result;
}
/*
* 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;
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 */
/* Insert "np" into "mf_trans" hashtable with key "np->nt_old_bnum" */
mf_hash_add_item(&mfp->mf_trans, (mf_hashitem_T *)np);
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;
{
NR_TRANS *np;
blocknr_T new_bnum;
np = (NR_TRANS *)mf_hash_find(&mfp->mf_trans, old_nr);
if (np == NULL) /* not found */
return old_nr;
mfp->mf_neg_count--;
new_bnum = np->nt_new_bnum;
/* remove entry from the trans list */
mf_hash_rem_item(&mfp->mf_trans, (mf_hashitem_T *)np);
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)
/*
* 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
{
#ifdef HAVE_FD_CLOEXEC
int fdflags = fcntl(mfp->mf_fd, F_GETFD);
if (fdflags >= 0 && (fdflags & FD_CLOEXEC) == 0)
fcntl(mfp->mf_fd, F_SETFD, fdflags | FD_CLOEXEC);
#endif
#ifdef HAVE_SELINUX
mch_copy_sec(fname, mfp->mf_fname);
#endif
mch_hide(mfp->mf_fname); /* try setting the 'hidden' flag */
}
}
/*
* Implementation of mf_hashtab_T follows.
*/
/*
* The number of buckets in the hashtable is increased by a factor of
* MHT_GROWTH_FACTOR when the average number of items per bucket
* exceeds 2 ^ MHT_LOG_LOAD_FACTOR.
*/
#define MHT_LOG_LOAD_FACTOR 6
#define MHT_GROWTH_FACTOR 2 /* must be a power of two */
/*
* Initialize an empty hash table.
*/
static void
mf_hash_init(mht)
mf_hashtab_T *mht;
{
vim_memset(mht, 0, sizeof(mf_hashtab_T));
mht->mht_buckets = mht->mht_small_buckets;
mht->mht_mask = MHT_INIT_SIZE - 1;
}
/*
* Free the array of a hash table. Does not free the items it contains!
* The hash table must not be used again without another mf_hash_init() call.
*/
static void
mf_hash_free(mht)
mf_hashtab_T *mht;
{
if (mht->mht_buckets != mht->mht_small_buckets)
vim_free(mht->mht_buckets);
}
/*
* Free the array of a hash table and all the items it contains.
*/
static void
mf_hash_free_all(mht)
mf_hashtab_T *mht;
{
long_u idx;
mf_hashitem_T *mhi;
mf_hashitem_T *next;
for (idx = 0; idx <= mht->mht_mask; idx++)
for (mhi = mht->mht_buckets[idx]; mhi != NULL; mhi = next)
{
next = mhi->mhi_next;
vim_free(mhi);
}
mf_hash_free(mht);
}
/*
* Find "key" in hashtable "mht".
* Returns a pointer to a mf_hashitem_T or NULL if the item was not found.
*/
static mf_hashitem_T *
mf_hash_find(mht, key)
mf_hashtab_T *mht;
blocknr_T key;
{
mf_hashitem_T *mhi;
mhi = mht->mht_buckets[key & mht->mht_mask];
while (mhi != NULL && mhi->mhi_key != key)
mhi = mhi->mhi_next;
return mhi;
}
/*
* Add item "mhi" to hashtable "mht".
* "mhi" must not be NULL.
*/
static void
mf_hash_add_item(mht, mhi)
mf_hashtab_T *mht;
mf_hashitem_T *mhi;
{
long_u idx;
idx = mhi->mhi_key & mht->mht_mask;
mhi->mhi_next = mht->mht_buckets[idx];
mhi->mhi_prev = NULL;
if (mhi->mhi_next != NULL)
mhi->mhi_next->mhi_prev = mhi;
mht->mht_buckets[idx] = mhi;
mht->mht_count++;
/*
* Grow hashtable when we have more thank 2^MHT_LOG_LOAD_FACTOR
* items per bucket on average
*/
if (mht->mht_fixed == 0
&& (mht->mht_count >> MHT_LOG_LOAD_FACTOR) > mht->mht_mask)
{
if (mf_hash_grow(mht) == FAIL)
{
/* stop trying to grow after first failure to allocate memory */
mht->mht_fixed = 1;
}
}
}
/*
* Remove item "mhi" from hashtable "mht".
* "mhi" must not be NULL and must have been inserted into "mht".
*/
static void
mf_hash_rem_item(mht, mhi)
mf_hashtab_T *mht;
mf_hashitem_T *mhi;
{
if (mhi->mhi_prev == NULL)
mht->mht_buckets[mhi->mhi_key & mht->mht_mask] = mhi->mhi_next;
else
mhi->mhi_prev->mhi_next = mhi->mhi_next;
if (mhi->mhi_next != NULL)
mhi->mhi_next->mhi_prev = mhi->mhi_prev;
mht->mht_count--;
/* We could shrink the table here, but it typically takes little memory,
* so why bother? */
}
/*
* Increase number of buckets in the hashtable by MHT_GROWTH_FACTOR and
* rehash items.
* Returns FAIL when out of memory.
*/
static int
mf_hash_grow(mht)
mf_hashtab_T *mht;
{
long_u i, j;
int shift;
mf_hashitem_T *mhi;
mf_hashitem_T *tails[MHT_GROWTH_FACTOR];
mf_hashitem_T **buckets;
size_t size;
size = (mht->mht_mask + 1) * MHT_GROWTH_FACTOR * sizeof(void *);
buckets = (mf_hashitem_T **)lalloc_clear(size, FALSE);
if (buckets == NULL)
return FAIL;
shift = 0;
while ((mht->mht_mask >> shift) != 0)
shift++;
for (i = 0; i <= mht->mht_mask; i++)
{
/*
* Traverse the items in the i-th original bucket and move them into
* MHT_GROWTH_FACTOR new buckets, preserving their relative order
* within each new bucket. Preserving the order is important because
* mf_get() tries to keep most recently used items at the front of
* each bucket.
*
* Here we strongly rely on the fact the hashes are computed modulo
* a power of two.
*/
vim_memset(tails, 0, sizeof(tails));
for (mhi = mht->mht_buckets[i]; mhi != NULL; mhi = mhi->mhi_next)
{
j = (mhi->mhi_key >> shift) & (MHT_GROWTH_FACTOR - 1);
if (tails[j] == NULL)
{
buckets[i + (j << shift)] = mhi;
tails[j] = mhi;
mhi->mhi_prev = NULL;
}
else
{
tails[j]->mhi_next = mhi;
mhi->mhi_prev = tails[j];
tails[j] = mhi;
}
}
for (j = 0; j < MHT_GROWTH_FACTOR; j++)
if (tails[j] != NULL)
tails[j]->mhi_next = NULL;
}
if (mht->mht_buckets != mht->mht_small_buckets)
vim_free(mht->mht_buckets);
mht->mht_buckets = buckets;
mht->mht_mask = (mht->mht_mask + 1) * MHT_GROWTH_FACTOR - 1;
return OK;
}
Jump to Line
Something went wrong with that request. Please try again.