Annotation of src/usr.bin/vim/memfile.c, Revision 1.1
1.1 ! downsj 1: /* $OpenBSD$ */
! 2: /* vi:set ts=4 sw=4:
! 3: *
! 4: * VIM - Vi IMproved by Bram Moolenaar
! 5: *
! 6: * Do ":help uganda" in Vim to read copying and usage conditions.
! 7: * Do ":help credits" in Vim to see a list of people who contributed.
! 8: */
! 9:
! 10: /* for debugging */
! 11: #define CHECK(c, s) if (c) printf(s)
! 12:
! 13: /*
! 14: * memfile.c: Contains the functions for handling blocks of memory which can
! 15: * be stored in a file. This is the implementation of a sort of virtual memory.
! 16: *
! 17: * A memfile consists of a sequence of blocks. The blocks numbered from 0
! 18: * upwards have been assigned a place in the actual file. The block number
! 19: * is equal to the page number in the file. The
! 20: * blocks with negative numbers are currently in memory only. They can be
! 21: * assigned a place in the file when too much memory is being used. At that
! 22: * moment they get a new, positive, number. A list is used for translation of
! 23: * negative to positive numbers.
! 24: *
! 25: * The size of a block is a multiple of a page size, normally the page size of
! 26: * the device the file is on. Most blocks are 1 page long. A Block of multiple
! 27: * pages is used for a line that does not fit in a single page.
! 28: *
! 29: * Each block can be in memory and/or in a file. The block stays in memory
! 30: * as long as it is locked. If it is no longer locked it can be swapped out to
! 31: * the file. It is only written to the file if it has been changed.
! 32: *
! 33: * Under normal operation the file is created when opening the memory file and
! 34: * deleted when closing the memory file. Only with recovery an existing memory
! 35: * file is opened.
! 36: */
! 37:
! 38: #if defined MSDOS || defined WIN32
! 39: # include <io.h> /* for lseek(), must be before vim.h */
! 40: #endif
! 41:
! 42: #include "vim.h"
! 43: #include "globals.h"
! 44: #include "proto.h"
! 45: #include "option.h"
! 46: #ifdef HAVE_FCNTL_H
! 47: # include <fcntl.h>
! 48: #endif
! 49:
! 50: /*
! 51: * Some systems have the page size in statfs, some in stat
! 52: */
! 53: #ifdef HAVE_SYS_STATFS_H
! 54: # include <sys/statfs.h>
! 55: # define STATFS statfs
! 56: # define F_BSIZE f_bsize
! 57: # ifdef MINT
! 58: # define fstatfs(fd, buf, len, nul) fstat((fd), (buf))
! 59: # endif
! 60: #else
! 61: # define STATFS stat
! 62: # define F_BSIZE st_blksize
! 63: # define fstatfs(fd, buf, len, nul) fstat((fd), (buf))
! 64: #endif
! 65:
! 66: /*
! 67: * for Amiga Dos 2.0x we use Flush
! 68: */
! 69: #ifdef AMIGA
! 70: # ifndef NO_ARP
! 71: extern int dos2; /* this is in amiga.c */
! 72: # endif
! 73: # ifdef SASC
! 74: # include <proto/dos.h>
! 75: # include <ios1.h> /* for chkufb() */
! 76: # endif
! 77: #endif
! 78:
! 79: #define MEMFILE_PAGE_SIZE 4096 /* default page size */
! 80:
! 81: static long total_mem_used = 0; /* total memory used for memfiles */
! 82:
! 83: static void mf_ins_hash __ARGS((MEMFILE *, BHDR *));
! 84: static void mf_rem_hash __ARGS((MEMFILE *, BHDR *));
! 85: static BHDR *mf_find_hash __ARGS((MEMFILE *, blocknr_t));
! 86: static void mf_ins_used __ARGS((MEMFILE *, BHDR *));
! 87: static void mf_rem_used __ARGS((MEMFILE *, BHDR *));
! 88: static BHDR *mf_release __ARGS((MEMFILE *, int));
! 89: static BHDR *mf_alloc_bhdr __ARGS((MEMFILE *, int));
! 90: static void mf_free_bhdr __ARGS((BHDR *));
! 91: static void mf_ins_free __ARGS((MEMFILE *, BHDR *));
! 92: static BHDR *mf_rem_free __ARGS((MEMFILE *));
! 93: static int mf_read __ARGS((MEMFILE *, BHDR *));
! 94: static int mf_write __ARGS((MEMFILE *, BHDR *));
! 95: static int mf_trans_add __ARGS((MEMFILE *, BHDR *));
! 96: static void mf_do_open __ARGS((MEMFILE *, char_u *, int));
! 97:
! 98: /*
! 99: * The functions for using a memfile:
! 100: *
! 101: * mf_open() open a new or existing memfile
! 102: * mf_open_file() open a swap file for an existing memfile
! 103: * mf_close() close (and delete) a memfile
! 104: * mf_new() create a new block in a memfile and lock it
! 105: * mf_get() get an existing block and lock it
! 106: * mf_put() unlock a block, may be marked for writing
! 107: * mf_free() remove a block
! 108: * mf_sync() sync changed parts of memfile to disk
! 109: * mf_release_all() release as much memory as possible
! 110: * mf_trans_del() may translate negative to positive block number
! 111: * mf_fullname() make file name full path (use before first :cd)
! 112: */
! 113:
! 114: /*
! 115: * mf_open: open an existing or new memory block file
! 116: *
! 117: * fname: name of file to use (NULL means no file at all)
! 118: * Note: fname must have been allocated, it is not copied!
! 119: * If opening the file fails, fname is NOT freed.
! 120: * trunc_file: if TRUE: file should be truncated when opening
! 121: *
! 122: * If fname != NULL and file cannot be opened, fail.
! 123: *
! 124: * return value: identifier for this memory block file.
! 125: */
! 126: MEMFILE *
! 127: mf_open(fname, trunc_file)
! 128: char_u *fname;
! 129: int trunc_file;
! 130: {
! 131: MEMFILE *mfp;
! 132: int i;
! 133: long size;
! 134: #ifdef UNIX
! 135: struct STATFS stf;
! 136: #endif
! 137:
! 138: if ((mfp = (MEMFILE *)alloc((unsigned)sizeof(MEMFILE))) == NULL)
! 139: return NULL;
! 140:
! 141: if (fname == NULL) /* no file for this memfile, use memory only */
! 142: {
! 143: mfp->mf_fname = NULL;
! 144: mfp->mf_xfname = NULL;
! 145: mfp->mf_fd = -1;
! 146: }
! 147: else
! 148: {
! 149: mf_do_open(mfp, fname, trunc_file); /* try to open the file */
! 150:
! 151: /* if the file cannot be opened, return here */
! 152: if (mfp->mf_fd < 0)
! 153: {
! 154: vim_free(mfp);
! 155: return NULL;
! 156: }
! 157: }
! 158:
! 159: mfp->mf_free_first = NULL; /* free list is empty */
! 160: mfp->mf_used_first = NULL; /* used list is empty */
! 161: mfp->mf_used_last = NULL;
! 162: mfp->mf_dirty = FALSE;
! 163: mfp->mf_used_count = 0;
! 164: for (i = 0; i < MEMHASHSIZE; ++i)
! 165: {
! 166: mfp->mf_hash[i] = NULL; /* hash lists are empty */
! 167: mfp->mf_trans[i] = NULL; /* trans lists are empty */
! 168: }
! 169: mfp->mf_page_size = MEMFILE_PAGE_SIZE;
! 170:
! 171: #ifdef UNIX
! 172: /*
! 173: * Try to set the page size equal to the block size of the device.
! 174: * Speeds up I/O a lot.
! 175: * NOTE: minimal block size depends on size of block 0 data! It's not done
! 176: * with a sizeof(), because block 0 is defined in memline.c (Sorry).
! 177: * The maximal block size is arbitrary.
! 178: */
! 179: if (mfp->mf_fd >= 0 &&
! 180: fstatfs(mfp->mf_fd, &stf, sizeof(struct statfs), 0) == 0 &&
! 181: stf.F_BSIZE >= 1048 && stf.F_BSIZE <= 50000)
! 182: mfp->mf_page_size = stf.F_BSIZE;
! 183: #endif
! 184:
! 185: if (mfp->mf_fd < 0 || trunc_file ||
! 186: (size = lseek(mfp->mf_fd, 0L, SEEK_END)) <= 0)
! 187: mfp->mf_blocknr_max = 0; /* no file or empty file */
! 188: else
! 189: mfp->mf_blocknr_max = size / mfp->mf_page_size;
! 190: mfp->mf_blocknr_min = -1;
! 191: mfp->mf_neg_count = 0;
! 192: mfp->mf_infile_count = mfp->mf_blocknr_max;
! 193: if (mfp->mf_fd < 0)
! 194: mfp->mf_used_count_max = 0; /* no limit */
! 195: else
! 196: mfp->mf_used_count_max = p_mm * 1024 / mfp->mf_page_size;
! 197:
! 198: return mfp;
! 199: }
! 200:
! 201: /*
! 202: * mf_open_file: open a file for an existing memfile. Used when updatecount
! 203: * set from 0 to some value.
! 204: *
! 205: * fname: name of file to use (NULL means no file at all)
! 206: * Note: fname must have been allocated, it is not copied!
! 207: * If opening the file fails, fname is NOT freed.
! 208: *
! 209: * return value: FAIL if file could not be opened, OK otherwise
! 210: */
! 211: int
! 212: mf_open_file(mfp, fname)
! 213: MEMFILE *mfp;
! 214: char_u *fname;
! 215: {
! 216: mf_do_open(mfp, fname, TRUE); /* try to open the file */
! 217:
! 218: if (mfp->mf_fd < 0)
! 219: return FAIL;
! 220:
! 221: mfp->mf_dirty = TRUE;
! 222: return OK;
! 223: }
! 224:
! 225: /*
! 226: * close a memory file and delete the associated file if 'del_file' is TRUE
! 227: */
! 228: void
! 229: mf_close(mfp, del_file)
! 230: MEMFILE *mfp;
! 231: int del_file;
! 232: {
! 233: BHDR *hp, *nextp;
! 234: NR_TRANS *tp, *tpnext;
! 235: int i;
! 236:
! 237: if (mfp == NULL) /* safety check */
! 238: return;
! 239: if (mfp->mf_fd >= 0)
! 240: {
! 241: if (close(mfp->mf_fd) < 0)
! 242: EMSG("Close error on swap file");
! 243: }
! 244: if (del_file && mfp->mf_fname != NULL)
! 245: vim_remove(mfp->mf_fname);
! 246: /* free entries in used list */
! 247: for (hp = mfp->mf_used_first; hp != NULL; hp = nextp)
! 248: {
! 249: total_mem_used -= hp->bh_page_count * mfp->mf_page_size;
! 250: nextp = hp->bh_next;
! 251: mf_free_bhdr(hp);
! 252: }
! 253: while (mfp->mf_free_first != NULL) /* free entries in free list */
! 254: vim_free(mf_rem_free(mfp));
! 255: for (i = 0; i < MEMHASHSIZE; ++i) /* free entries in trans lists */
! 256: for (tp = mfp->mf_trans[i]; tp != NULL; tp = tpnext)
! 257: {
! 258: tpnext = tp->nt_next;
! 259: vim_free(tp);
! 260: }
! 261: vim_free(mfp->mf_fname);
! 262: vim_free(mfp->mf_xfname);
! 263: vim_free(mfp);
! 264: }
! 265:
! 266: /*
! 267: * get a new block
! 268: *
! 269: * negative: TRUE if negative block number desired (data block)
! 270: */
! 271: BHDR *
! 272: mf_new(mfp, negative, page_count)
! 273: MEMFILE *mfp;
! 274: int negative;
! 275: int page_count;
! 276: {
! 277: BHDR *hp; /* new BHDR */
! 278: BHDR *freep; /* first block in free list */
! 279: char_u *p;
! 280:
! 281: /*
! 282: * If we reached the maximum size for the used memory blocks, release one
! 283: * If a BHDR is returned, use it and adjust the page_count if necessary.
! 284: */
! 285: hp = mf_release(mfp, page_count);
! 286:
! 287: /*
! 288: * Decide on the number to use:
! 289: * If there is a free block, use its number.
! 290: * Otherwise use mf_block_min for a negative number, mf_block_max for
! 291: * a positive number.
! 292: */
! 293: freep = mfp->mf_free_first;
! 294: if (!negative && freep != NULL && freep->bh_page_count >= page_count)
! 295: {
! 296: /*
! 297: * If the block in the free list has more pages, take only the number
! 298: * of pages needed and allocate a new BHDR with data
! 299: *
! 300: * If the number of pages matches and mf_release did not return a BHDR,
! 301: * use the BHDR from the free list and allocate the data
! 302: *
! 303: * If the number of pages matches and mf_release returned a BHDR,
! 304: * just use the number and free the BHDR from the free list
! 305: */
! 306: if (freep->bh_page_count > page_count)
! 307: {
! 308: if (hp == NULL && (hp = mf_alloc_bhdr(mfp, page_count)) == NULL)
! 309: return NULL;
! 310: hp->bh_bnum = freep->bh_bnum;
! 311: freep->bh_bnum += page_count;
! 312: freep->bh_page_count -= page_count;
! 313: }
! 314: else if (hp == NULL) /* need to allocate memory for this block */
! 315: {
! 316: if ((p = (char_u *)alloc(mfp->mf_page_size * page_count)) == NULL)
! 317: return NULL;
! 318: hp = mf_rem_free(mfp);
! 319: hp->bh_data = p;
! 320: }
! 321: else /* use the number, remove entry from free list */
! 322: {
! 323: freep = mf_rem_free(mfp);
! 324: hp->bh_bnum = freep->bh_bnum;
! 325: vim_free(freep);
! 326: }
! 327: }
! 328: else /* get a new number */
! 329: {
! 330: if (hp == NULL && (hp = mf_alloc_bhdr(mfp, page_count)) == NULL)
! 331: return NULL;
! 332: if (negative)
! 333: {
! 334: hp->bh_bnum = mfp->mf_blocknr_min--;
! 335: mfp->mf_neg_count++;
! 336: }
! 337: else
! 338: {
! 339: hp->bh_bnum = mfp->mf_blocknr_max;
! 340: mfp->mf_blocknr_max += page_count;
! 341: }
! 342: }
! 343: hp->bh_flags = BH_LOCKED | BH_DIRTY; /* new block is always dirty */
! 344: mfp->mf_dirty = TRUE;
! 345: hp->bh_page_count = page_count;
! 346: mf_ins_used(mfp, hp);
! 347: mf_ins_hash(mfp, hp);
! 348:
! 349: return hp;
! 350: }
! 351:
! 352: /*
! 353: * get existing block 'nr' with 'page_count' pages
! 354: *
! 355: * Note: The caller should first check a negative nr with mf_trans_del()
! 356: */
! 357: BHDR *
! 358: mf_get(mfp, nr, page_count)
! 359: MEMFILE *mfp;
! 360: blocknr_t nr;
! 361: int page_count;
! 362: {
! 363: BHDR *hp;
! 364: /* doesn't exist */
! 365: if (nr >= mfp->mf_blocknr_max || nr <= mfp->mf_blocknr_min)
! 366: return NULL;
! 367:
! 368: /*
! 369: * see if it is in the cache
! 370: */
! 371: hp = mf_find_hash(mfp, nr);
! 372: if (hp == NULL) /* not in the hash list */
! 373: {
! 374: if (nr < 0 || nr >= mfp->mf_infile_count) /* can't be in the file */
! 375: return NULL;
! 376:
! 377: /* could check here if the block is in the free list */
! 378:
! 379: /*
! 380: * Check if we need to flush an existing block.
! 381: * If so, use that block.
! 382: * If not, allocate a new block.
! 383: */
! 384: hp = mf_release(mfp, page_count);
! 385: if (hp == NULL && (hp = mf_alloc_bhdr(mfp, page_count)) == NULL)
! 386: return NULL;
! 387:
! 388: hp->bh_bnum = nr;
! 389: hp->bh_flags = 0;
! 390: hp->bh_page_count = page_count;
! 391: if (mf_read(mfp, hp) == FAIL) /* cannot read the block! */
! 392: {
! 393: mf_free_bhdr(hp);
! 394: return NULL;
! 395: }
! 396: }
! 397: else
! 398: {
! 399: mf_rem_used(mfp, hp); /* remove from list, insert in front below */
! 400: mf_rem_hash(mfp, hp);
! 401: }
! 402:
! 403: hp->bh_flags |= BH_LOCKED;
! 404: mf_ins_used(mfp, hp); /* put in front of used list */
! 405: mf_ins_hash(mfp, hp); /* put in front of hash list */
! 406:
! 407: return hp;
! 408: }
! 409:
! 410: /*
! 411: * release the block *hp
! 412: *
! 413: * dirty: Block must be written to file later
! 414: * infile: Block should be in file (needed for recovery)
! 415: *
! 416: * no return value, function cannot fail
! 417: */
! 418: void
! 419: mf_put(mfp, hp, dirty, infile)
! 420: MEMFILE *mfp;
! 421: BHDR *hp;
! 422: int dirty;
! 423: int infile;
! 424: {
! 425: int flags;
! 426:
! 427: flags = hp->bh_flags;
! 428: CHECK((flags & BH_LOCKED) == 0, "block was not locked");
! 429: flags &= ~BH_LOCKED;
! 430: if (dirty)
! 431: {
! 432: flags |= BH_DIRTY;
! 433: mfp->mf_dirty = TRUE;
! 434: }
! 435: hp->bh_flags = flags;
! 436: if (infile)
! 437: mf_trans_add(mfp, hp); /* may translate negative in positive nr */
! 438: }
! 439:
! 440: /*
! 441: * block *hp is no longer in used, may put it in the free list of memfile *mfp
! 442: */
! 443: void
! 444: mf_free(mfp, hp)
! 445: MEMFILE *mfp;
! 446: BHDR *hp;
! 447: {
! 448: vim_free(hp->bh_data); /* free the memory */
! 449: mf_rem_hash(mfp, hp); /* get *hp out of the hash list */
! 450: mf_rem_used(mfp, hp); /* get *hp out of the used list */
! 451: if (hp->bh_bnum < 0)
! 452: {
! 453: vim_free(hp); /* don't want negative numbers in free list */
! 454: mfp->mf_neg_count--;
! 455: }
! 456: else
! 457: mf_ins_free(mfp, hp); /* put *hp in the free list */
! 458: }
! 459:
! 460: /*
! 461: * sync the memory file *mfp to disk
! 462: * if 'all' is FALSE blocks with negative numbers are not synced, even when
! 463: * they are dirty!
! 464: * if 'check_char' is TRUE, stop syncing when a character becomes available,
! 465: * but sync at least one block.
! 466: * if 'do_fsync' is TRUE make sure buffers are flushed to disk, so they will
! 467: * survive a system crash.
! 468: *
! 469: * Return FAIL for failure, OK otherwise
! 470: */
! 471: int
! 472: mf_sync(mfp, all, check_char, do_fsync)
! 473: MEMFILE *mfp;
! 474: int all;
! 475: int check_char;
! 476: int do_fsync;
! 477: {
! 478: int status;
! 479: BHDR *hp;
! 480: #ifdef SYNC_DUP_CLOSE
! 481: int fd;
! 482: #endif
! 483:
! 484: if (mfp->mf_fd < 0) /* there is no file, nothing to do */
! 485: {
! 486: mfp->mf_dirty = FALSE;
! 487: return FAIL;
! 488: }
! 489:
! 490: /*
! 491: * sync from last to first (may reduce the probability of an inconsistent
! 492: * file) If a write fails, it is very likely caused by a full filesystem.
! 493: * Then we only try to write blocks within the existing file. If that also
! 494: * fails then we give up.
! 495: */
! 496: status = OK;
! 497: for (hp = mfp->mf_used_last; hp != NULL; hp = hp->bh_prev)
! 498: if ((all || hp->bh_bnum >= 0) && (hp->bh_flags & BH_DIRTY) &&
! 499: (status == OK || (hp->bh_bnum >= 0 &&
! 500: hp->bh_bnum < mfp->mf_infile_count)))
! 501: {
! 502: if (mf_write(mfp, hp) == FAIL)
! 503: {
! 504: if (status == FAIL) /* double error: quit syncing */
! 505: break;
! 506: status = FAIL;
! 507: }
! 508: if (check_char && mch_char_avail()) /* char available now */
! 509: break;
! 510: }
! 511:
! 512: /*
! 513: * If the whole list is flushed, the memfile is not dirty anymore.
! 514: * In case of an error this flag is also set, to avoid trying all the time.
! 515: */
! 516: if (hp == NULL || status == FAIL)
! 517: mfp->mf_dirty = FALSE;
! 518:
! 519: if (do_fsync && *p_sws != NUL)
! 520: {
! 521: #if defined(UNIX)
! 522: # ifdef HAVE_FSYNC
! 523: /*
! 524: * most Unixes have the very useful fsync() function, just what we need.
! 525: * However, with OS/2 and EMX it is also available, but there are
! 526: * reports of bad problems with it (a bug in HPFS.IFS).
! 527: * So we disable use of it here in case someone tries to be smart
! 528: * and changes conf_os2.h... (even though there is no __EMX__ test
! 529: * in the #if, as __EMX__ does not have sync(); we hope for a timely
! 530: * sync from the system itself).
! 531: */
! 532: # if defined(__EMX__)
! 533: error "Dont use fsync with EMX! Read emxdoc.doc or emxfix01.doc for info."
! 534: # endif
! 535: if (STRCMP(p_sws, "fsync") == 0)
! 536: {
! 537: if (fsync(mfp->mf_fd))
! 538: status = FAIL;
! 539: }
! 540: else
! 541: # endif
! 542: sync();
! 543: #endif
! 544: #ifdef DJGPP
! 545: if (_dos_commit(mfp->mf_fd))
! 546: status = FAIL;
! 547: #else
! 548: # ifdef SYNC_DUP_CLOSE
! 549: /*
! 550: * MSdos is a bit more work: Duplicate the file handle and close it.
! 551: * This should flush the file to disk.
! 552: */
! 553: if ((fd = dup(mfp->mf_fd)) >= 0)
! 554: close(fd);
! 555: # endif
! 556: #endif
! 557: #ifdef AMIGA
! 558: /*
! 559: * Flush() only exists for AmigaDos 2.0.
! 560: * For 1.3 it should be done with close() + open(), but then the risk
! 561: * is that the open() may fail and lose the file....
! 562: */
! 563: # ifndef NO_ARP
! 564: if (dos2)
! 565: # endif
! 566: # ifdef SASC
! 567: {
! 568: struct UFB *fp = chkufb(mfp->mf_fd);
! 569:
! 570: if (fp != NULL)
! 571: Flush(fp->ufbfh);
! 572: }
! 573: # else
! 574: # ifdef _DCC
! 575: {
! 576: BPTR fh = (BPTR)fdtofh(mfp->mf_fd);
! 577:
! 578: if (fh != 0)
! 579: Flush(fh);
! 580: }
! 581: # else /* assume Manx */
! 582: Flush(_devtab[mfp->mf_fd].fd);
! 583: # endif
! 584: # endif
! 585: #endif /* AMIGA */
! 586: }
! 587:
! 588: return status;
! 589: }
! 590:
! 591: /*
! 592: * insert block *hp in front of hashlist of memfile *mfp
! 593: */
! 594: static void
! 595: mf_ins_hash(mfp, hp)
! 596: MEMFILE *mfp;
! 597: BHDR *hp;
! 598: {
! 599: BHDR *hhp;
! 600: int hash;
! 601:
! 602: hash = MEMHASH(hp->bh_bnum);
! 603: hhp = mfp->mf_hash[hash];
! 604: hp->bh_hash_next = hhp;
! 605: hp->bh_hash_prev = NULL;
! 606: if (hhp != NULL)
! 607: hhp->bh_hash_prev = hp;
! 608: mfp->mf_hash[hash] = hp;
! 609: }
! 610:
! 611: /*
! 612: * remove block *hp from hashlist of memfile list *mfp
! 613: */
! 614: static void
! 615: mf_rem_hash(mfp, hp)
! 616: MEMFILE *mfp;
! 617: BHDR *hp;
! 618: {
! 619: if (hp->bh_hash_prev == NULL)
! 620: mfp->mf_hash[MEMHASH(hp->bh_bnum)] = hp->bh_hash_next;
! 621: else
! 622: hp->bh_hash_prev->bh_hash_next = hp->bh_hash_next;
! 623:
! 624: if (hp->bh_hash_next)
! 625: hp->bh_hash_next->bh_hash_prev = hp->bh_hash_prev;
! 626: }
! 627:
! 628: /*
! 629: * look in hash lists of memfile *mfp for block header with number 'nr'
! 630: */
! 631: static BHDR *
! 632: mf_find_hash(mfp, nr)
! 633: MEMFILE *mfp;
! 634: blocknr_t nr;
! 635: {
! 636: BHDR *hp;
! 637:
! 638: for (hp = mfp->mf_hash[MEMHASH(nr)]; hp != NULL; hp = hp->bh_hash_next)
! 639: if (hp->bh_bnum == nr)
! 640: break;
! 641: return hp;
! 642: }
! 643:
! 644: /*
! 645: * insert block *hp in front of used list of memfile *mfp
! 646: */
! 647: static void
! 648: mf_ins_used(mfp, hp)
! 649: MEMFILE *mfp;
! 650: BHDR *hp;
! 651: {
! 652: hp->bh_next = mfp->mf_used_first;
! 653: mfp->mf_used_first = hp;
! 654: hp->bh_prev = NULL;
! 655: if (hp->bh_next == NULL) /* list was empty, adjust last pointer */
! 656: mfp->mf_used_last = hp;
! 657: else
! 658: hp->bh_next->bh_prev = hp;
! 659: mfp->mf_used_count += hp->bh_page_count;
! 660: total_mem_used += hp->bh_page_count * mfp->mf_page_size;
! 661: }
! 662:
! 663: /*
! 664: * remove block *hp from used list of memfile *mfp
! 665: */
! 666: static void
! 667: mf_rem_used(mfp, hp)
! 668: MEMFILE *mfp;
! 669: BHDR *hp;
! 670: {
! 671: if (hp->bh_next == NULL) /* last block in used list */
! 672: mfp->mf_used_last = hp->bh_prev;
! 673: else
! 674: hp->bh_next->bh_prev = hp->bh_prev;
! 675: if (hp->bh_prev == NULL) /* first block in used list */
! 676: mfp->mf_used_first = hp->bh_next;
! 677: else
! 678: hp->bh_prev->bh_next = hp->bh_next;
! 679: mfp->mf_used_count -= hp->bh_page_count;
! 680: total_mem_used -= hp->bh_page_count * mfp->mf_page_size;
! 681: }
! 682:
! 683: /*
! 684: * Release the least recently used block from the used list if the number
! 685: * of used memory blocks gets to big.
! 686: *
! 687: * Return the block header to the caller, including the memory block, so
! 688: * it can be re-used. Make sure the page_count is right.
! 689: */
! 690: static BHDR *
! 691: mf_release(mfp, page_count)
! 692: MEMFILE *mfp;
! 693: int page_count;
! 694: {
! 695: BHDR *hp;
! 696:
! 697: /*
! 698: * don't release a block if
! 699: * there is no file for this memfile
! 700: * or
! 701: * there is no limit to the number of blocks for this memfile or
! 702: * the maximum is not reached yet
! 703: * and
! 704: * total memory used is not up to 'maxmemtot'
! 705: */
! 706: if (mfp->mf_fd < 0 || ((mfp->mf_used_count < mfp->mf_used_count_max ||
! 707: mfp->mf_used_count_max == 0) &&
! 708: (total_mem_used >> 10) < p_mmt))
! 709: return NULL;
! 710:
! 711: for (hp = mfp->mf_used_last; hp != NULL; hp = hp->bh_prev)
! 712: if (!(hp->bh_flags & BH_LOCKED))
! 713: break;
! 714: if (hp == NULL) /* not a single one that can be released */
! 715: return NULL;
! 716:
! 717: /*
! 718: * If the block is dirty, write it.
! 719: * If the write fails we don't free it.
! 720: */
! 721: if ((hp->bh_flags & BH_DIRTY) && mf_write(mfp, hp) == FAIL)
! 722: return NULL;
! 723:
! 724: mf_rem_used(mfp, hp);
! 725: mf_rem_hash(mfp, hp);
! 726:
! 727: /*
! 728: * If a BHDR is returned, make sure that the page_count of bh_data is right
! 729: */
! 730: if (hp->bh_page_count != page_count)
! 731: {
! 732: vim_free(hp->bh_data);
! 733: if ((hp->bh_data = alloc(mfp->mf_page_size * page_count)) == NULL)
! 734: {
! 735: vim_free(hp);
! 736: return NULL;
! 737: }
! 738: hp->bh_page_count = page_count;
! 739: }
! 740: return hp;
! 741: }
! 742:
! 743: /*
! 744: * release as many blocks as possible
! 745: * Used in case of out of memory
! 746: *
! 747: * return TRUE if any memory was released
! 748: */
! 749: int
! 750: mf_release_all()
! 751: {
! 752: BUF *buf;
! 753: MEMFILE *mfp;
! 754: BHDR *hp;
! 755: int retval = FALSE;
! 756:
! 757: for (buf = firstbuf; buf != NULL; buf = buf->b_next)
! 758: {
! 759: mfp = buf->b_ml.ml_mfp;
! 760: if (mfp != NULL && mfp->mf_fd >= 0) /* only if there is a memfile with a file */
! 761: for (hp = mfp->mf_used_last; hp != NULL; )
! 762: {
! 763: if (!(hp->bh_flags & BH_LOCKED) &&
! 764: (!(hp->bh_flags & BH_DIRTY) || mf_write(mfp, hp) != FAIL))
! 765: {
! 766: mf_rem_used(mfp, hp);
! 767: mf_rem_hash(mfp, hp);
! 768: mf_free_bhdr(hp);
! 769: hp = mfp->mf_used_last; /* re-start, list was changed */
! 770: retval = TRUE;
! 771: }
! 772: else
! 773: hp = hp->bh_prev;
! 774: }
! 775: }
! 776: return retval;
! 777: }
! 778:
! 779: /*
! 780: * Allocate a block header and a block of memory for it
! 781: */
! 782: static BHDR *
! 783: mf_alloc_bhdr(mfp, page_count)
! 784: MEMFILE *mfp;
! 785: int page_count;
! 786: {
! 787: BHDR *hp;
! 788:
! 789: if ((hp = (BHDR *)alloc((unsigned)sizeof(BHDR))) != NULL)
! 790: {
! 791: if ((hp->bh_data = (char_u *)alloc(mfp->mf_page_size * page_count))
! 792: == NULL)
! 793: {
! 794: vim_free(hp); /* not enough memory */
! 795: return NULL;
! 796: }
! 797: hp->bh_page_count = page_count;
! 798: }
! 799: return hp;
! 800: }
! 801:
! 802: /*
! 803: * Free a block header and the block of memory for it
! 804: */
! 805: static void
! 806: mf_free_bhdr(hp)
! 807: BHDR *hp;
! 808: {
! 809: vim_free(hp->bh_data);
! 810: vim_free(hp);
! 811: }
! 812:
! 813: /*
! 814: * insert entry *hp in the free list
! 815: */
! 816: static void
! 817: mf_ins_free(mfp, hp)
! 818: MEMFILE *mfp;
! 819: BHDR *hp;
! 820: {
! 821: hp->bh_next = mfp->mf_free_first;
! 822: mfp->mf_free_first = hp;
! 823: }
! 824:
! 825: /*
! 826: * remove the first entry from the free list and return a pointer to it
! 827: * Note: caller must check that mfp->mf_free_first is not NULL!
! 828: */
! 829: static BHDR *
! 830: mf_rem_free(mfp)
! 831: MEMFILE *mfp;
! 832: {
! 833: BHDR *hp;
! 834:
! 835: hp = mfp->mf_free_first;
! 836: mfp->mf_free_first = hp->bh_next;
! 837: return hp;
! 838: }
! 839:
! 840: /*
! 841: * read a block from disk
! 842: *
! 843: * Return FAIL for failure, OK otherwise
! 844: */
! 845: static int
! 846: mf_read(mfp, hp)
! 847: MEMFILE *mfp;
! 848: BHDR *hp;
! 849: {
! 850: long_u offset;
! 851: unsigned page_size;
! 852: unsigned size;
! 853:
! 854: if (mfp->mf_fd < 0) /* there is no file, can't read */
! 855: return FAIL;
! 856:
! 857: page_size = mfp->mf_page_size;
! 858: offset = page_size * hp->bh_bnum;
! 859: size = page_size * hp->bh_page_count;
! 860: if ((long_u)lseek(mfp->mf_fd, offset, SEEK_SET) != offset)
! 861: {
! 862: EMSG("Seek error in swap file read");
! 863: return FAIL;
! 864: }
! 865: if ((unsigned)read(mfp->mf_fd, (char *)hp->bh_data, (size_t)size) != size)
! 866: {
! 867: EMSG("Read error in swap file");
! 868: return FAIL;
! 869: }
! 870: return OK;
! 871: }
! 872:
! 873: /*
! 874: * write a block to disk
! 875: *
! 876: * Return FAIL for failure, OK otherwise
! 877: */
! 878: static int
! 879: mf_write(mfp, hp)
! 880: MEMFILE *mfp;
! 881: BHDR *hp;
! 882: {
! 883: long_u offset; /* offset in the file */
! 884: blocknr_t nr; /* block nr which is being written */
! 885: BHDR *hp2;
! 886: unsigned page_size; /* number of bytes in a page */
! 887: unsigned page_count; /* number of pages written */
! 888: unsigned size; /* number of bytes written */
! 889:
! 890: if (mfp->mf_fd < 0) /* there is no file, can't write */
! 891: return FAIL;
! 892:
! 893: if (hp->bh_bnum < 0) /* must assign file block number */
! 894: if (mf_trans_add(mfp, hp) == FAIL)
! 895: return FAIL;
! 896:
! 897: page_size = mfp->mf_page_size;
! 898:
! 899: /*
! 900: * We don't want gaps in the file. Write the blocks in front of *hp
! 901: * to extend the file.
! 902: * If block 'mf_infile_count' is not in the hash list, it has been
! 903: * freed. Fill the space in the file with data from the current block.
! 904: */
! 905: for (;;)
! 906: {
! 907: nr = hp->bh_bnum;
! 908: if (nr > mfp->mf_infile_count) /* beyond end of file */
! 909: {
! 910: nr = mfp->mf_infile_count;
! 911: hp2 = mf_find_hash(mfp, nr); /* NULL catched below */
! 912: }
! 913: else
! 914: hp2 = hp;
! 915:
! 916: offset = page_size * nr;
! 917: if ((long_u)lseek(mfp->mf_fd, offset, SEEK_SET) != offset)
! 918: {
! 919: EMSG("Seek error in swap file write");
! 920: return FAIL;
! 921: }
! 922: if (hp2 == NULL) /* freed block, fill with dummy data */
! 923: page_count = 1;
! 924: else
! 925: page_count = hp2->bh_page_count;
! 926: size = page_size * page_count;
! 927: if ((unsigned)write(mfp->mf_fd,
! 928: (char *)(hp2 == NULL ? hp : hp2)->bh_data, (size_t)size) != size)
! 929: {
! 930: /*
! 931: * Avoid repeating the error message, this mostly happens when the
! 932: * disk is full. We give the message again only after a succesful
! 933: * write or when hitting a key. We keep on trying, in case some
! 934: * space becomes available.
! 935: */
! 936: if (!did_swapwrite_msg)
! 937: EMSG("Write error in swap file");
! 938: did_swapwrite_msg = TRUE;
! 939: return FAIL;
! 940: }
! 941: did_swapwrite_msg = FALSE;
! 942: if (hp2 != NULL) /* written a non-dummy block */
! 943: hp2->bh_flags &= ~BH_DIRTY;
! 944: /* appended to the file */
! 945: if (nr + (blocknr_t)page_count > mfp->mf_infile_count)
! 946: mfp->mf_infile_count = nr + page_count;
! 947: if (nr == hp->bh_bnum) /* written the desired block */
! 948: break;
! 949: }
! 950: return OK;
! 951: }
! 952:
! 953: /*
! 954: * Make block number for *hp positive and add it to the translation list
! 955: *
! 956: * Return FAIL for failure, OK otherwise
! 957: */
! 958: static int
! 959: mf_trans_add(mfp, hp)
! 960: MEMFILE *mfp;
! 961: BHDR *hp;
! 962: {
! 963: BHDR *freep;
! 964: blocknr_t new_bnum;
! 965: int hash;
! 966: NR_TRANS *np;
! 967: int page_count;
! 968:
! 969: if (hp->bh_bnum >= 0) /* it's already positive */
! 970: return OK;
! 971:
! 972: if ((np = (NR_TRANS *)alloc((unsigned)sizeof(NR_TRANS))) == NULL)
! 973: return FAIL;
! 974:
! 975: /*
! 976: * get a new number for the block.
! 977: * If the first item in the free list has sufficient pages, use its number
! 978: * Otherwise use mf_blocknr_max.
! 979: */
! 980: freep = mfp->mf_free_first;
! 981: page_count = hp->bh_page_count;
! 982: if (freep != NULL && freep->bh_page_count >= page_count)
! 983: {
! 984: new_bnum = freep->bh_bnum;
! 985: /*
! 986: * If the page count of the free block was larger, recude it.
! 987: * If the page count matches, remove the block from the free list
! 988: */
! 989: if (freep->bh_page_count > page_count)
! 990: {
! 991: freep->bh_bnum += page_count;
! 992: freep->bh_page_count -= page_count;
! 993: }
! 994: else
! 995: {
! 996: freep = mf_rem_free(mfp);
! 997: vim_free(freep);
! 998: }
! 999: }
! 1000: else
! 1001: {
! 1002: new_bnum = mfp->mf_blocknr_max;
! 1003: mfp->mf_blocknr_max += page_count;
! 1004: }
! 1005:
! 1006: np->nt_old_bnum = hp->bh_bnum; /* adjust number */
! 1007: np->nt_new_bnum = new_bnum;
! 1008:
! 1009: mf_rem_hash(mfp, hp); /* remove from old hash list */
! 1010: hp->bh_bnum = new_bnum;
! 1011: mf_ins_hash(mfp, hp); /* insert in new hash list */
! 1012:
! 1013: hash = MEMHASH(np->nt_old_bnum); /* insert in trans list */
! 1014: np->nt_next = mfp->mf_trans[hash];
! 1015: mfp->mf_trans[hash] = np;
! 1016: if (np->nt_next != NULL)
! 1017: np->nt_next->nt_prev = np;
! 1018: np->nt_prev = NULL;
! 1019:
! 1020: return OK;
! 1021: }
! 1022:
! 1023: /*
! 1024: * Lookup a tranlation from the trans lists and delete the entry
! 1025: *
! 1026: * Return the positive new number when found, the old number when not found
! 1027: */
! 1028: blocknr_t
! 1029: mf_trans_del(mfp, old_nr)
! 1030: MEMFILE *mfp;
! 1031: blocknr_t old_nr;
! 1032: {
! 1033: int hash;
! 1034: NR_TRANS *np;
! 1035: blocknr_t new_bnum;
! 1036:
! 1037: hash = MEMHASH(old_nr);
! 1038: for (np = mfp->mf_trans[hash]; np != NULL; np = np->nt_next)
! 1039: if (np->nt_old_bnum == old_nr)
! 1040: break;
! 1041: if (np == NULL) /* not found */
! 1042: return old_nr;
! 1043:
! 1044: mfp->mf_neg_count--;
! 1045: new_bnum = np->nt_new_bnum;
! 1046: if (np->nt_prev != NULL) /* remove entry from the trans list */
! 1047: np->nt_prev->nt_next = np->nt_next;
! 1048: else
! 1049: mfp->mf_trans[hash] = np->nt_next;
! 1050: if (np->nt_next != NULL)
! 1051: np->nt_next->nt_prev = np->nt_prev;
! 1052: vim_free(np);
! 1053:
! 1054: return new_bnum;
! 1055: }
! 1056:
! 1057: /*
! 1058: * Set mfp->mf_xfname according to mfp->mf_fname and some other things.
! 1059: * Don't get the full path name if did_cd is TRUE, then fname should
! 1060: * already be a full path name.
! 1061: */
! 1062: void
! 1063: mf_set_xfname(mfp)
! 1064: MEMFILE *mfp;
! 1065: {
! 1066: mfp->mf_xfname = NULL;
! 1067: if (!did_cd)
! 1068: mfp->mf_xfname = FullName_save(mfp->mf_fname);
! 1069: }
! 1070:
! 1071: /*
! 1072: * Make the name of the file used for the memfile a full path.
! 1073: * Used before doing a :cd
! 1074: */
! 1075: void
! 1076: mf_fullname(mfp)
! 1077: MEMFILE *mfp;
! 1078: {
! 1079: if (mfp != NULL && mfp->mf_fname != NULL && mfp->mf_xfname != NULL)
! 1080: {
! 1081: vim_free(mfp->mf_fname);
! 1082: mfp->mf_fname = mfp->mf_xfname;
! 1083: mfp->mf_xfname = NULL;
! 1084: }
! 1085: }
! 1086:
! 1087: /*
! 1088: * return TRUE if there are any translations pending for 'mfp'
! 1089: */
! 1090: int
! 1091: mf_need_trans(mfp)
! 1092: MEMFILE *mfp;
! 1093: {
! 1094: return (mfp->mf_fname != NULL && mfp->mf_neg_count > 0);
! 1095: }
! 1096:
! 1097: #if 1 /* included for beta release, TODO: remove later */
! 1098: /*
! 1099: * print statistics for a memfile (for debugging)
! 1100: */
! 1101: void
! 1102: mf_statistics()
! 1103: {
! 1104: MEMFILE *mfp;
! 1105: BHDR *hp;
! 1106: int used = 0;
! 1107: int locked = 0;
! 1108: int dirty = 0;
! 1109: int nfree = 0;
! 1110: int negative = 0;
! 1111:
! 1112: mfp = curbuf->b_ml.ml_mfp;
! 1113: if (mfp == NULL)
! 1114: MSG("No memfile");
! 1115: else
! 1116: {
! 1117: for (hp = mfp->mf_used_first; hp != NULL; hp = hp->bh_next)
! 1118: {
! 1119: ++used;
! 1120: if (hp->bh_flags & BH_LOCKED)
! 1121: ++locked;
! 1122: if (hp->bh_flags & BH_DIRTY)
! 1123: ++dirty;
! 1124: if (hp->bh_bnum < 0)
! 1125: ++negative;
! 1126: }
! 1127: for (hp = mfp->mf_free_first; hp != NULL; hp = hp->bh_next)
! 1128: ++nfree;
! 1129: sprintf((char *)IObuff, "%d used (%d locked, %d dirty, %d (%d) negative), %d free",
! 1130: used, locked, dirty, negative, (int)mfp->mf_neg_count, nfree);
! 1131: msg(IObuff);
! 1132: sprintf((char *)IObuff, "Total mem used is %ld bytes", total_mem_used);
! 1133: msg(IObuff);
! 1134: }
! 1135: }
! 1136: #endif
! 1137:
! 1138: /*
! 1139: * open a swap file for a memfile
! 1140: */
! 1141: static void
! 1142: mf_do_open(mfp, fname, trunc_file)
! 1143: MEMFILE *mfp;
! 1144: char_u *fname;
! 1145: int trunc_file;
! 1146: {
! 1147: mfp->mf_fname = fname;
! 1148: /*
! 1149: * Get the full path name before the open, because this is
! 1150: * not possible after the open on the Amiga.
! 1151: * fname cannot be NameBuff, because it must have been allocated.
! 1152: */
! 1153: mf_set_xfname(mfp);
! 1154:
! 1155: /*
! 1156: * try to open the file
! 1157: */
! 1158: mfp->mf_fd = open((char *)fname,
! 1159: (trunc_file ? (O_CREAT | O_RDWR | O_TRUNC) : (O_RDONLY)) | O_EXTRA
! 1160:
! 1161: #ifdef AMIGA /* Amiga has no mode argument */
! 1162: );
! 1163: #endif
! 1164: #ifdef UNIX /* open in rw------- mode */
! 1165: , (mode_t)0600);
! 1166: #endif
! 1167: #if defined(MSDOS) || defined(WIN32) || defined(__EMX__)
! 1168: , S_IREAD | S_IWRITE); /* open read/write */
! 1169: #endif
! 1170: #ifdef VMS /* open in rw------- mode */
! 1171: , 0600);
! 1172: #endif
! 1173:
! 1174: /*
! 1175: * If the file cannot be opened, use memory only
! 1176: */
! 1177: if (mfp->mf_fd < 0)
! 1178: {
! 1179: vim_free(mfp->mf_xfname);
! 1180: mfp->mf_fname = NULL;
! 1181: mfp->mf_xfname = NULL;
! 1182: }
! 1183: }
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