+
+/*---------- File handling ----------*/
+
+int acquire_lock(Tcl_Interp *ip, PathBuf *pb, int *lockfd_r) {
+ /* *lockfd_r must be -1 on entry. If may be set to >=0 even
+ * on error, and must be closed by the caller. */
+ mode_t umask, lockmode;
+ struct flock fl;
+
+ umask= umask(~(mode_t)0);
+ umask(umask);
+
+ lockmode= 0666 & ~((umask & 0444)>>1);
+ /* Remove r where umask would remove w;
+ * eg umask intending 0664 here gives 0660 */
+
+ *lockfd_r= open(pathbuf_sfx(".lock"), O_RDONLY|O_CREAT, lockmode);
+ if (*lockfd_r < 0)
+ return cht_posixerr(ip, errno, "could not open/create lockfile");
+
+ fl.l_type= F_WRLCK;
+ fl.l_whence= SEEK_SET;
+ fl.l_start= 0;
+ fl.l_end= 0;
+ fl.l_pid= getpid();
+
+ r= fcntl(*lockfd_r, F_SETLK, &fl);
+ if (r == -1) {
+ if (errno == EACCES || errno == EAGAIN)
+ return cht_staticerr(ip, "lock held by another process", "CDB LOCKED");
+ else return cht_posixerr(ip, errno, "unexpected error from fcntl while"
+ " acquiring lock");
+ }
+}
+
+/*---------- Log reading ----------*/
+
+static int readlognum(FILE *f, int delim, int *num_r) {
+ int c;
+ char numbuf[20], *p, *ep;
+ unsigned long ul;
+
+ p= numbuf;
+ for (;;) {
+ c= getc(f); if (c==EOF) return -2;
+ if (c == delim) break;
+ if (!isdigit((unsigned char)c)) return -2;
+ *p++= c;
+ if (p == numbuf+sizeof(numbuf)) return -2;
+ }
+ if (p == numbuf) return -2;
+ *p= 0;
+
+ errno=0; ul= strtoul(numbuf, &ep, 10);
+ if (*ep || errno || ul >= INT_MAX/2) return -2;
+ *num_r= ul;
+ return 0;
+}
+
+static int readstorelogrecord(FILE *f, HashTable *ht,
+ void (*updatefn)(HashTable*, HashDatum*,
+ HashDatum*)) {
+ /* returns:
+ * 0 for OK
+ * -1 eof
+ * -2 corrupt or error
+ * -3 got newline indicating end
+ */
+ int keylen, vallen;
+ HashDatum *key, *val;
+
+ c= getc(f);
+ if (c==EOF) { if (feof(f)) return -1; return -2; }
+ if (c=='\n') return -3;
+ if (c!='+') return -2;
+
+ rc= readlognum(f, ',', &keylen); if (rc) return rc;
+ rc= readlognum(f, ':', &vallen); if (rc) return rc;
+
+ key= htd_prep(keylen);
+ val= htd_prep(vallen);
+
+ r= fread(htd_fillptr(key), 1,keylen, f);
+ if (r!=keylen) goto x2_free_keyval;
+
+ c= getc(f); if (c!='-') goto x2_free_keyval;
+ c= getc(f); if (c!='>') goto x2_free_keyval;
+
+ r= fread(htd_fillptr(val), 1,vallen, f);
+ if (r!=vallen) goto x2_free_keyval;
+
+ updatefn(ht, key, val);
+ return TCL_OK;
+
+x2_free_keyval;
+ TFREE(val);
+ TFREE(key);
+ return -2;
+}
+
+/*---------- Creating ----------*/
+
+int cht_do_cdbwr_create_empty(ClientData cd, Tcl_Interp *ip,
+ const char *pathb) {
+ static const char *const toremoves[]= {
+ ".main", ".cdb", ".log", ".tmp", 0
+ }
+
+ Pathbuf pb;
+ int lock_fd=-1, fd=-1, rc;
+ const char *const *toremove;
+
+ pathbuf_init(&pb, pathb);
+ rc= acquire_lock(ip, &pb, &lock_fd); if (rc) goto x_rc;
+
+ fd= open(pathbuf_sfx(".main"), O_RDWR|O_CREAT|O_EXCL, 0666);
+ if (fd <= 0) PE("create new database file");
+
+ for (toremoves=toremove; *toremove; toremove++) {
+ r= remove(*toremove);
+ if (r && errno != ENOENT)
+ PE("delete possible spurious file during creation");
+ }
+
+ rc= TCL_OK;
+
+ x_rc:
+ maybe_close(fd);
+ maybe_close(lock_fd);
+ pathbuf_free(&pb);
+ return rc;
+}
+
+/*---------- Opening ----------*/
+
+int cht_do_cdbwr_open(ClientData cd, Tcl_Interp *ip,
+ const char *pathb, Tcl_Obj *on_info, void **result) {
+ const Cdbwr_SubCommand *subcmd= cd;
+ int rc, mainfd=-1;
+ Rw *rw;
+ struct stat stab;
+ fpos_t logrecstart;
+
+ rw= TALLOC(sizeof(*rw));
+ rc= ht_setup(&rw->logincore); if (rc) { TFREE(rw); return rc; }
+ rw->cdb_fd= rw->lock_fd= -1; rw->logfile= 0;
+ pathbuf_init(&rw->pbsome, &pathb);
+ pathbuf_init(&rw->pbother, &pathb);
+ rw->autocompact= 1;
+
+ mainfd= open(pathbuf_sfx(&rw->pbsome,".main"), O_RDONLY);
+ if (mainfd<0) PE("open exist3ing database file .main");
+ rc= acquire_lock(ip, &rw->pbsome, &rw->lock_fd); if (rc) goto x_rc;
+
+ r= stat(mainfd, &stab); if (r) PE("fstat .main");
+ rw->mainsz= stab.st_size;
+
+ rw->cdb_fd= open(pathbuf_sfx(&rw->pbsome,".cdb"), O_RDONLY);
+ if (fd>=0) {
+ r= cdb_init(&rw->cdb, rw->cdb_fd);
+ if (r) {
+ rc= cht_posixerr(ip, errno, "failed to initialise cdb reader");
+ close(rw->cdb_fd); rw->cdb_fd= -1; goto x_rc;
+ }
+ } else if (errno == ENOENT) {
+ if (rw->mainsz) {
+ rc= cht_staticerr(ip, ".cdb does not exist but .main is nonempty -"
+ " .cdb must have been accidentally deleted!",
+ "CDB CDBMISSING");
+ goto x_rc;
+ }
+ /* fine */
+ } else {
+ PE("open .cdb");
+ }
+
+ rw->logfile= fopen(pathbuf_sfx(&rw->pbsome,".log"), "r+");
+ if (!rw->logfile) {
+ if (errno != ENOENT) PE("failed to open .log during open");
+ rw->logfile= fopen(rw->pbsome.buf, "w");
+ if (!rw->logfile) PE("create .log during (clean) open");
+ } else { /* rw->logfile */
+ r= fstat(fileno(rw->logfile), &stab);
+ if (r==-1) PE("fstat .log during open");
+ rc= infocb(rw, "open-dirty-start", "log=%luby",
+ (unsigned long)stab.st_size);
+ if (rc) goto x_rc;
+
+ for (;;) {
+ r= fgetpos(rw->logfile, &logrecstart);
+ if (r) PE("fgetpos .log during (dirty) open");
+ r= readstorelogrecord(rw->logfile, &rw->logincore, ht_update);
+ if (ferror(rw->logfile)) {
+ rc= cht_posixerr(ip, errno, "error reading .log during (dirty) open");
+ goto x_rc;
+ }
+ if (r==-1) {
+ break;
+ } else if (r==-2 || r==-3) {
+ char buf[100];
+ r= fgetpos(rw->logfile, &logjunkpos);
+ if (r) PE("fgetpos .log during report of junk in dirty open");
+
+ snprintf(buf,sizeof(buf), "CDB SYNTAX LOG %lu %lu",
+ (unsigned long)junkpos, (unsigned long)logrecstart);
+
+ if (!(subcmd->flags & RWSCF_OKJUNK)) {
+ Tcl_SetObjErrorCode(ip, Tcl_NewStringObj(buf,-1));
+ snprintf(buf,sizeof(buf),"%lu",(unsigned long)junkpos);
+ Tcl_ResetResult(ip);
+ Tcl_AppendResult(ip, "syntax error (junk) in .log during"
+ " (dirty) open, at file position ", buf, (char*)0);
+ rc= TCL_ERROR;
+ goto x_rc;
+ }
+ rc= infocb(rw, "open-dirty-junk", "errorfpos=%luby {%s}",
+ (unsigned long)logjunkpos, buf);
+ if (rc) goto x_rc;
+
+ r= fsetpos(rw->logfile, logrecstart);
+ if (r) PE("failed to fsetpos .log before junk during dirty open");
+
+ r= ftruncate(fileno(rw->logfile), logrecstart);
+ if (r) PE("ftruncate .log to chop junk during dirty open");
+ } else {
+ assert(!r);
+ }
+ }
+ }
+ /* now log is positioned for appending and everything is read */
+
+ *result= rw;
+ maybe_close(mainfd);
+ return TCL_OK;
+
+ x_rc:
+ rw_close(0,rw);
+ maybe_close(mainfd);
+ return rc;
+}
+
+/*---------- Compacting ----------*/
+
+static int compact_core(Tcl_Interp *ip, Rw *rw, unsigned long logsz) {
+ /* creates new .cdb and .main
+ * closes logfile
+ * leaves .log with old data
+ * leaves cdb fd open onto old db
+ * leaves logincore full of crap
+ */
+ int rc;
+ int cdbfd, cdbmaking;
+ struct ht_forall_ctx {
+ struct cdb_make cdbm;
+ FILE *mainfile;
+ int count;
+ } addctx;
+
+ a.mainfile= 0;
+ cdbfd= -1;
+ cdbmaking= 0;
+
+ r= fclose(rw->logfile);
+ if (r) { rc= cht_posixerr(ip, errno, "data loss! failed to fclose"
+ " logfile during compact"); goto x_rc; }
+ rw->logfile= 0;
+
+ rc= infocb(ip, rw, "compact-start", "log=%luby main=%luby",
+ logsize, (unsigned long)rw->mainsz);
+ if (rc) goto x_rc;
+
+ /* merge unsuperseded records from main into hash table */
+
+ a.mainfile= fopen(pathbuf_sfx(&rw_pbsome,".main"), "r");
+ if (!a.mainfile) PE("failed to open .main for reading during compact");
+
+ for (;;) {
+ r= readstorelogrecord(a.mainfile, &rw->logincore, ht_maybeupdate);
+ if (ferror(a.mainfile)) { rc= cht_posixerr(ip, errno, "error reading"
+ " .main during compact"); goto x_rc;
+ }
+ if (r==-3) {
+ break;
+ } else if (r==-1 || r==-2) {
+ r= fgetpos(a.mainfile, &errpos);
+ if (r) PE("fgetpos .main during report of syntax error");
+ snprintf(buf,sizeof(buf), "CDB SYNTAX MAIN %lu", (uunsigned long)errpos);
+ Tcl_SetObjErrorCode(ip, Tcl_NewStringObj(buf,-1));
+ snprintf(buf,sizeof(buf), "%lu", (uunsigned long)errpos);
+ Tcl_ResetResult(ip);
+ Tcl_AppendResult(ip, "syntax error in .main during"
+ " compact, at file position ", buf, (char*)0);
+ rc= TCL_ERROR;
+ goto x_rc;
+ } else {
+ assert(!rc);
+ }
+ }
+ fclose(a.mainfile);
+ a.mainfile= 0;
+
+ /* create new cdb */
+
+ cdbfd= open(pathbuf_sfx(&rw->pbsome,".tmp"), O_WRONLY|O_CREAT|O_TRUNC, 0666);
+ if (cdbfd<0) PE("create .tmp for new cdb during compact");
+
+ r= cdb_make_start(&a.cdbm, cdbfd);
+ if (r) PE("cdb_make_start during compact");
+ cdbmaking= 1;
+
+ r= ht_forall(&rw->logincore, addto_cdb, &addctx);
+ if (r) PE("cdb_make_add during compact");
+
+ r= cdb_make_finish(&a.cdbm, cdbfd);
+ if(r) PE("cdb_make_finish during compact");
+ cdbmaking= 0;
+
+ r= fdatasync(cdbfd); if (r) PE("fdatasync new cdb during compact");
+ r= close(cdbfd); if (r) PE("close new cdb during compact");
+ cdbfd= -1;
+
+ r= rename(rw->pbsome.buf, pathbuf_sfx(&rw->pbother,".cdb"));
+ if (r) PE("install new .cdb during compact");
+
+ /* create new main */
+
+ a.mainfile= fopen(pathbuf_sfx(&rw->pbsome,".tmp"), "w");
+ if (!a.mainfile) PE("create .tmp for new main during compact");
+
+ a.count= 0;
+ r= ht_forall(&rw->logincore, addto_main, a.mainfile);
+ if (r) { rc= cht_posixerr(ip, r, "error writing to new .main"
+ " during compact"); goto x_rc; }
+
+ r= fflush(a.mainfile); if (r) PE("fflush new main during compact");
+ r= fdatasync(fileno(a.mainfile));
+ if (r) PE("fdatasync new main during compact");
+
+ r= fclose(a.mainfile); if (r) PE("fclose new main during compact");
+ a.mainfile= 0;
+
+ r= rename(rw->pbsome.buf, pathbuf_sfx(&rw->pbother,".main"));
+ if (r) PE("install new .main during compact");
+
+ /* done! */
+
+ rc= infocb(ip, rw, "compact-end", "log=%luby main=%luby",
+ logsize, (unsigned long)rw->mainsz);
+ if (rc) goto x_rc;
+
+ rc= TCL_OK;
+x_rc:
+ if (mainfile) fclose(mainfile);
+ if (cdbmaking) cdb_make_finish(&a.cdbm, cdbfd);
+ maybe_close(cdbfd);
+ remove(pathbuf_sfx(&rw->pbsome,".tmp")); /* for tidyness */
+}
+
+static void compact_forclose(Tcl_Interp *ip, Rw *rw) {
+ long logsz;
+ int rc;
+
+ logsz= ftell(rw->logfile);
+ if (logsz < 0) PE("ftell logfile (during tidy close)");
+
+ rc= compact_core(ip, rw, logsz); if (rc) goto x_rc;
+
+ r= remove(pathbuf_sfx(&rw->pbsome,".log"));
+ if (r) PE("remove .log (during tidy close)");
+}
+
+int cht_do_cdbwr_close(ClientData cd, Tcl_Interp *ip, void *rw_v) {
+ Rw *rw= rw_v;
+ int rc, compact_rc, infocb_rc;
+
+ if (rw->autocompact) compact_rc= compact_forclose(ip, rw);
+ else compact_rc= TCL_OK;
+
+ rc= rw_close(ip,rw);
+ infocb_rc= infocb_close(rw);
+
+ cht_tabledataid_disposing(ip, rw_v, &cdbtcl_rwdatabases);
+ if (!rc) rc= compact_rc;
+ if (!rc) rc= infocb_rc;
+ return rc;
+}
+
+
+int cht_do_cdbwr_lookup(ClientData cd, Tcl_Interp *ip, void *db, Tcl_Obj *key, Tcl_Obj **result);
+int cht_do_cdbwr_lookup_hb(ClientData cd, Tcl_Interp *ip, void *db, HBytes_Value key, HBytes_Value *result);
+int cht_do_cdbwr_update(ClientData cd, Tcl_Interp *ip, void *db, Tcl_Obj *key, Tcl_Obj *value);
+int cht_do_cdbwr_update_hb(ClientData cd, Tcl_Interp *ip, void *db, HBytes_Value key, HBytes_Value value);
+int cht_do_cdbwr_update_quick(ClientData cd, Tcl_Interp *ip, void *db, Tcl_Obj *key, Tcl_Obj *value);
+int cht_do_cdbwr_update_quick_hb(ClientData cd, Tcl_Interp *ip, void *db, HBytes_Value key, HBytes_Value value);
~ian / chiark-tcl.git / blobdiff