X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?a=blobdiff_plain;ds=sidebyside;f=cdb%2Fwriteable.c;h=a73be821a001a894b0114920a06e4b045f1ab985;hb=f16e3e0cf0a2b965643df01e24ef59e1393da78d;hp=3c718d83fd813f63e26645839cfba0f02e0bf1a5;hpb=2aaa6d9084b8a950151d64b4fe7a483be59b5722;p=chiark-tcl.git

diff --git a/cdb/writeable.c b/cdb/writeable.c
index 3c718d8..a73be82 100644
--- a/cdb/writeable.c
+++ b/cdb/writeable.c
@@ -15,10 +15,6 @@ static void maybe_close(int fd) {
   if (fd>=0) close(fd);
 }
 
-#define PE(m) do{						\
-    rc= cht_posixerr(ip, errno, "failed to " m); goto x_rc;	\
-  }while(0)
-
 /*==================== Subsystems and subtypes ====================*/
 
 /*---------- Pathbuf ----------*/
@@ -27,14 +23,13 @@ typedef struct Pathbuf {
   char *buf, *sfx;
 } Pathbuf;
 
-#define MAX_SUFFIX 4
+#define MAX_SUFFIX 5
 
 static void pathbuf_init(Pathbuf *pb, const char *pathb) {
   int l= strlen(pathb);
-  pb->buf= TALLOC(l + 4);
+  pb->buf= TALLOC(l + MAX_SUFFIX + 1);
   memcpy(pb->buf, pathb, l);
   pb->sfx= pb->buf + l;
-  *pb->sfx++= '.';
 }
 static const char *pathbuf_sfx(Pathbuf *pb, const char *suffix) {
   assert(strlen(suffix) <= MAX_SUFFIX);
@@ -68,11 +63,6 @@ static HashValue *htv_prep(int len) {
 static Byte *htv_fillptr(HashValue *hd) {
   return hd->data;
 }
-#if 0
-static void htv_fill(HashValue *hd, const Byte *data) {
-  memcpy(hd->data, data, hd->len);
-}
-#endif
 
 static void ht_setup(HashTable *ht) {
   Tcl_InitHashTable(&ht->t, TCL_STRING_KEYS);
@@ -97,6 +87,15 @@ static void ht_maybeupdate(HashTable *ht, const char *key,
   Tcl_SetHashValue(he, val_eat);
 }
 
+static const HashValue *ht_lookup(HashTable *ht, const char *key) {
+  Tcl_HashEntry *he;
+  
+  he= Tcl_FindHashEntry(&ht->t, key);
+  if (!he) return 0;
+  
+  return Tcl_GetHashValue(he);
+}
+
 static int ht_forall(HashTable *ht,
 		     int (*fn)(const char *key, HashValue *val,
 			       struct ht_forall_ctx *ctx),
@@ -166,11 +165,13 @@ static int rw_close(Tcl_Interp *ip, Rw *rw) {
   }
 
   pathbuf_free(&rw->pbsome); pathbuf_free(&rw->pbother);
-  TFREE(rw);
   return rc;
 }
 
-static void destroy_cdbrw_idtabcb(Tcl_Interp *ip, void *rw) { rw_close(0,rw); }
+static void destroy_cdbrw_idtabcb(Tcl_Interp *ip, void *rw) {
+  rw_close(0,rw);
+  TFREE(rw);
+}
 const IdDataSpec cdbtcl_rwdatabases= {
   "cdb-rwdb", "cdb-openrwdatabases-table", destroy_cdbrw_idtabcb
 };
@@ -191,7 +192,7 @@ static int acquire_lock(Tcl_Interp *ip, Pathbuf *pb, int *lockfd_r) {
   /* Remove r where umask would remove w;
    * eg umask intending 0664 here gives 0660 */
   
-  *lockfd_r= open(pathbuf_sfx(pb,".lock"), O_RDONLY|O_CREAT, lockmode);
+  *lockfd_r= open(pathbuf_sfx(pb,".lock"), O_RDWR|O_CREAT, lockmode);
   if (*lockfd_r < 0)
     return cht_posixerr(ip, errno, "could not open/create lockfile");
 
@@ -212,7 +213,7 @@ static int acquire_lock(Tcl_Interp *ip, Pathbuf *pb, int *lockfd_r) {
   return TCL_OK;
 }
 
-/*---------- Log reading ----------*/
+/*---------- Log reading and writing ----------*/
 
 static int readlognum(FILE *f, int delim, int *num_r) {
   int c;
@@ -255,7 +256,7 @@ static int readstorelogrecord(FILE *f, HashTable *ht,
   int c, rc, r;
 
   c= getc(f);
-  if (c==EOF) { if (feof(f)) return -1; return -2; }
+  if (c==EOF) { return feof(f) ? -1 : -2; }
   if (c=='\n') return -3;
   if (c!='+') return -2;
 
@@ -276,6 +277,8 @@ static int readstorelogrecord(FILE *f, HashTable *ht,
   r= fread(htv_fillptr(val), 1,vallen, f);
   if (r!=vallen) goto x2_free_keyval;
 
+  c= getc(f);  if (c!='\n') goto x2_free_keyval;
+
   rc= omitfn ? omitfn(val, ctx) : TCL_OK;
   if (rc) { assert(rc>0); TFREE(val); }
   else updatefn(ht, key, val);
@@ -289,36 +292,64 @@ static int readstorelogrecord(FILE *f, HashTable *ht,
   return -2;
 }
 
+static int writerecord(FILE *f, const char *key, const HashValue *val) {
+  int r;
+
+  r= fprintf(f, "+%d,%d:%s->", strlen(key), val->len, key);
+  if (r<0) return -1;
+  
+  r= fwrite(val->data, 1, val->len, f);
+  if (r != val->len) return -1;
+
+  r= putc('\n', f);
+  if (r==EOF) return -1;
+
+  return 0;
+}
+
 /*---------- 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
-  };
+  static const char *const toremoves[]= { ".cdb", ".log", ".tmp", 0 };
 
-  Pathbuf pb;
-  int lock_fd=-1, fd=-1, rc, r;
+  Pathbuf pb, pbmain;
+  int lock_fd=-1, rc, r;
+  FILE *f= 0;
   const char *const *toremove;
+  struct stat stab;
 
   pathbuf_init(&pb, pathb);
+  pathbuf_init(&pbmain, pathb);
+
   rc= acquire_lock(ip, &pb, &lock_fd);  if (rc) goto x_rc;
-  
-  fd= open(pathbuf_sfx(&pb, ".main"), O_RDWR|O_CREAT|O_EXCL, 0666);
-  if (fd <= 0) PE("create new database file");
+
+  r= lstat(pathbuf_sfx(&pbmain, ".main"), &stab);
+  if (!r) { rc= cht_staticerr(ip, "database already exists during creation",
+			      "CDB ALREADY-EXISTS");  goto x_rc; }
+  if (errno != ENOENT) PE("check for existing database .main during creation");
 
   for (toremove=toremoves; *toremove; toremove++) {
-    r= remove(*toremove);
+    r= remove(pathbuf_sfx(&pb, *toremove));
     if (r && errno != ENOENT)
       PE("delete possible spurious file during creation");
   }
   
+  f= fopen(pathbuf_sfx(&pb, ".tmp"), "w");
+  if (!f) PE("create new database .tmp");  
+  r= putc('\n', f);  if (r==EOF) PE("write sentinel to new database .tmp");
+  r= fclose(f);  f=0;  if (r) PE("close new database .tmp during creation");
+
+  r= rename(pb.buf, pbmain.buf);
+  if (r) PE("install new database .tmp as .main (finalising creation)");
+  
   rc= TCL_OK;
 
  x_rc:
-  maybe_close(fd);
+  if (f) fclose(f);
   maybe_close(lock_fd);
   pathbuf_free(&pb);
+  pathbuf_free(&pbmain);
   return rc;
 }
 
@@ -384,6 +415,7 @@ int cht_do_cdbwr_open(ClientData cd, Tcl_Interp *ip, const char *pathb,
   off_t logrecstart, logjunkpos;
 
   rw= TALLOC(sizeof(*rw));
+  rw->ix= -1;
   ht_setup(&rw->logincore);
   cht_scriptinv_init(&rw->on_info);
   cht_scriptinv_init(&rw->on_lexminval);
@@ -392,15 +424,14 @@ int cht_do_cdbwr_open(ClientData cd, Tcl_Interp *ip, const char *pathb,
   pathbuf_init(&rw->pbother, pathb);
   rw->autocompact= 1;
 
-  if (on_lexminval) {
-    rc= cht_scriptinv_set(&rw->on_lexminval, ip, on_lexminval, 0);
-    if (rc) goto x_rc;
-  } else {
-    rw->on_lexminval.llength= 0;
-  }
+  rc= cht_scriptinv_set(&rw->on_info, ip, on_info, 0);
+  if (rc) goto x_rc;
+
+  rc= cht_scriptinv_set(&rw->on_lexminval, ip, on_lexminval, 0);
+  if (rc) goto x_rc;
 
   mainfd= open(pathbuf_sfx(&rw->pbsome,".main"), O_RDONLY);
-  if (mainfd<0) PE("open exist3ing database file .main");
+  if (mainfd<0) PE("open existing database file .main");
   rc= acquire_lock(ip, &rw->pbsome, &rw->lock_fd);  if (rc) goto x_rc;
 
   r= fstat(mainfd, &stab);  if (r) PE("fstat .main");
@@ -410,8 +441,8 @@ int cht_do_cdbwr_open(ClientData cd, Tcl_Interp *ip, const char *pathb,
   if (rw->cdb_fd >=0) {
     rc= cdbinit(ip, rw);  if (rc) goto x_rc;
   } else if (errno == ENOENT) {
-    if (rw->mainsz) {
-      rc= cht_staticerr(ip, ".cdb does not exist but .main is nonempty -"
+    if (rw->mainsz > 1) {
+      rc= cht_staticerr(ip, ".cdb does not exist but .main is >1byte -"
 			" .cdb must have been accidentally deleted!",
 			"CDB CDBMISSING");
       goto x_rc;
@@ -482,25 +513,32 @@ int cht_do_cdbwr_open(ClientData cd, Tcl_Interp *ip, const char *pathb,
 
  x_rc:
   rw_close(0,rw);
+  TFREE(rw);
   maybe_close(mainfd);
   return rc;
 }
 
+int cht_do_cdbwr_open_okjunk(ClientData cd, Tcl_Interp *ip, const char *pathb,
+		      Tcl_Obj *on_info, Tcl_Obj *on_lexminval,
+		      void **result) {
+  return cht_do_cdbwr_open(cd,ip,pathb,on_info,on_lexminval,result);
+}
+
 /*==================== COMPACTION ====================*/
 
 struct ht_forall_ctx {
   struct cdb_make cdbm;
   FILE *mainfile;
-  int lexminvall;
   long *reccount;
-  const char *lexminval;
+  int lexminvall;
+  const char *lexminval; /* may be invalid if lexminvall <= 0 */
 };
 
 /*---------- helper functions ----------*/
 
 static int expiredp(const HashValue *val, struct ht_forall_ctx *a) {
   int r, l;
-  if (!val->len) return 0;
+  if (!val->len || a->lexminvall<=0) return 0;
   l= val->len < a->lexminvall ? val->len : a->lexminvall;
   r= memcmp(val->data, a->lexminval, l);
   if (r>0) return 0;
@@ -524,17 +562,8 @@ static int addto_cdb(const char *key, HashValue *val,
 
 static int addto_main(const char *key, HashValue *val,
 		      struct ht_forall_ctx *a) {
-  int r;
-
   (*a->reccount)++;
-  
-  r= fprintf(a->mainfile, "+%d,%d:%s->", strlen(key), val->len, key);
-  if (r<0) return -1;
-  
-  r= fwrite(val->data, 1, val->len, a->mainfile);
-  if (r != val->len) return -1;
-
-  return 0;
+  return writerecord(a->mainfile, key, val);
 }
 
 /*---------- compact main entrypoint ----------*/
@@ -569,7 +598,7 @@ static int compact_core(Tcl_Interp *ip, Rw *rw, unsigned long logsz,
 	     logsz, (unsigned long)rw->mainsz);
   if (rc) goto x_rc;
 
-  if (rw->on_lexminval.llength) {
+  if (cht_scriptinv_interp(&rw->on_lexminval)) {
     rc= cht_scriptinv_invoke_fg(&rw->on_lexminval, 0,0);
     if (rc) goto x_rc;
 
@@ -583,7 +612,7 @@ static int compact_core(Tcl_Interp *ip, Rw *rw, unsigned long logsz,
     rc= ht_forall(&rw->logincore, delete_ifexpired, &a);
 
   } else {
-    a.lexminval= "";
+    a.lexminvall= 0;
   }
 
   /* merge unsuperseded records from main into hash table */
@@ -596,19 +625,23 @@ static int compact_core(Tcl_Interp *ip, Rw *rw, unsigned long logsz,
 			  expiredp, &a,
 			  ht_maybeupdate);
     if (ferror(a.mainfile)) { rc= cht_posixerr(ip, errno, "error reading"
-                         " .main during compact"); goto x_rc;
-    }
+                         " .main during compact"); goto x_rc; }
     if (r==-3) {
       break;
     } else if (r==-1 || r==-2) {
       errpos= ftello(a.mainfile);
       if (errpos<0) PE("ftello .main during report of syntax error");
-      snprintf(buf,sizeof(buf), "CDB SYNTAX MAIN %lu", (unsigned long)errpos);
+      snprintf(buf,sizeof(buf), "CDB %s MAIN %lu",
+	       r==-1 ? "TRUNCATED" : "SYNTAX", (unsigned long)errpos);
       Tcl_SetObjErrorCode(ip, Tcl_NewStringObj(buf,-1));
       snprintf(buf,sizeof(buf), "%lu", (unsigned long)errpos);
       Tcl_ResetResult(ip);
-      Tcl_AppendResult(ip, "syntax error in .main during"
-		       " compact, at file position ", buf, (char*)0);
+      Tcl_AppendResult(ip,
+		       r==-1 ? "unexpected eof (truncated file)"
+		       " in .main during compact, at file position "
+		       : "syntax error"
+		       " in .main during compact, at file position ",
+		       buf, (char*)0);
       rc= TCL_ERROR;
       goto x_rc;
     } else {
@@ -649,6 +682,9 @@ static int compact_core(Tcl_Interp *ip, Rw *rw, unsigned long logsz,
   r= ht_forall(&rw->logincore, addto_main, &a);
   if (r) { rc= cht_posixerr(ip, r, "error writing to new .main"
 			    " during compact");  goto x_rc; }
+
+  r= putc('\n', a.mainfile);
+  if (r==EOF) PE("write trailing \n to main during compact");
   
   r= fflush(a.mainfile);  if (r) PE("fflush new main during compact");
   r= fdatasync(fileno(a.mainfile));
@@ -667,7 +703,7 @@ static int compact_core(Tcl_Interp *ip, Rw *rw, unsigned long logsz,
 
   /* done! */
   
-  rc= infocb(ip, rw, "compact-end", "main=%luby nrecs=%l",
+  rc= infocb(ip, rw, "compact-end", "main=%luby nrecs=%ld",
 	     (unsigned long)rw->mainsz, *a.reccount);
   if (rc) goto x_rc;
 
@@ -727,12 +763,13 @@ int cht_do_cdbwr_close(ClientData cd, Tcl_Interp *ip, void *rw_v) {
   if (rc_close) rc= rc_close;
   
   cht_tabledataid_disposing(ip, rw_v, &cdbtcl_rwdatabases);
+  TFREE(rw);
   return rc;
 }
 
 /*---------- Other compaction-related entrypoints ----------*/
 
-static int compact_keeopen(Tcl_Interp *ip, Rw *rw, int force) {
+static int compact_keepopen(Tcl_Interp *ip, Rw *rw, int force) {
   off_t logsz;
   long reccount;
   int rc, r;
@@ -741,7 +778,7 @@ static int compact_keeopen(Tcl_Interp *ip, Rw *rw, int force) {
   if (logsz < 0) return cht_posixerr(ip, errno, "ftell .log"
 				       " during compact check or force");
 
-  if (!force && logsz < rw->mainsz / 10 + 1000) return TCL_OK;
+  if (!force && logsz < rw->mainsz / 2 + 1000) return TCL_OK;
 
   rc= compact_core(ip, rw, logsz, &reccount);  if (rc) goto x_rc;
 
@@ -764,16 +801,16 @@ static int compact_keeopen(Tcl_Interp *ip, Rw *rw, int force) {
 
 x_rc:
   /* doom! all updates fail after this (because rw->logfile is 0), and
-   * we may be usin a lot more RAM than would be ideal.  Program will
+   * we may be using a lot more RAM than would be ideal.  Program will
    * have to reopen if it really wants sanity. */
   return rc;
 }
 
 int cht_do_cdbwr_compact_force(ClientData cd, Tcl_Interp *ip, void *rw_v) {
-  return compact_keeopen(ip, rw_v, 1);
+  return compact_keepopen(ip, rw_v, 1);
 }
 int cht_do_cdbwr_compact_check(ClientData cd, Tcl_Interp *ip, void *rw_v) {
-  return compact_keeopen(ip, rw_v, 0);
+  return compact_keepopen(ip, rw_v, 0);
 }
 
 int cht_do_cdbwr_compact_explicit(ClientData cd, Tcl_Interp *ip, void *rw_v) {
@@ -786,3 +823,93 @@ int cht_do_cdbwr_compact_auto(ClientData cd, Tcl_Interp *ip, void *rw_v) {
   rw->autocompact= 1;
   return TCL_OK;
 }
+
+/*---------- Updateing ----------*/
+
+static int update(Tcl_Interp *ip, Rw *rw, const char *key,
+		  const Byte *data, int dlen) {
+  HashValue *val;
+  int rc, r;
+
+  if (!rw->logfile) return cht_staticerr
+    (ip, "previous compact failed; cdbwr must be closed and reopened "
+     "before any further updates", "CDB BROKEN");
+  
+  val= htv_prep(dlen);  assert(val);
+  memcpy(htv_fillptr(val), data, dlen);
+
+  r= writerecord(rw->logfile, key, val);
+  if (!r) r= fflush(rw->logfile);
+  if (r) PE("write update to logfile");
+
+  ht_update(&rw->logincore, key, val);
+
+  if (!rw->autocompact) return TCL_OK;
+  return compact_keepopen(ip, rw, 0);
+
+ x_rc:
+  TFREE(val);
+  return rc;
+}  
+
+int cht_do_cdbwr_update(ClientData cd, Tcl_Interp *ip,
+			void *rw_v, const char *key, Tcl_Obj *value) {
+  int dlen;
+  const char *data;
+  data= Tcl_GetStringFromObj(value, &dlen);  assert(data);
+  return update(ip, rw_v, key, data, dlen);
+}
+
+int cht_do_cdbwr_update_hb(ClientData cd, Tcl_Interp *ip,
+			   void *rw_v, const char *key, HBytes_Value value) {
+  return update(ip, rw_v, key, cht_hb_data(&value), cht_hb_len(&value));
+}
+
+int cht_do_cdbwr_delete(ClientData cd, Tcl_Interp *ip, void *rw_v,
+			const char *key) {
+  return update(ip, rw_v, key, 0, 0);
+}
+
+/*---------- Lookups ----------*/
+
+static int lookup_rw(Tcl_Interp *ip, void *rw_v, const char *key,
+		    const Byte **data_r, int *len_r /* -1 => notfound */) {
+  Rw *rw= rw_v;
+  const HashValue *val;
+
+  val= ht_lookup(&rw->logincore, key);
+  if (val) {
+    if (val->len) { *data_r= val->data; *len_r= val->len; return TCL_OK; }
+    else { *data_r= 0; *len_r= -1; return TCL_OK; }
+  }
+
+  return cht_cdb_lookup_cdb(ip, &rw->cdb, key, strlen(key), data_r, len_r);
+} 
+
+int cht_do_cdbwr_lookup(ClientData cd, Tcl_Interp *ip, void *rw_v,
+			const char *key, Tcl_Obj *def,
+			Tcl_Obj **result) {
+  const Byte *data;
+  int dlen, r;
+  
+  r= lookup_rw(ip, rw_v, key, &data, &dlen);  if (r) return r;
+  return cht_cdb_donesomelookup(ip, rw_v, def, result, data, dlen,
+				cht_cdb_storeanswer_string);
+}
+  
+int cht_do_cdbwr_lookup_hb(ClientData cd, Tcl_Interp *ip, void *rw_v,
+			   const char *key, Tcl_Obj *def,
+			   Tcl_Obj **result) {
+  const Byte *data;
+  int dlen, r;
+  
+  r= lookup_rw(ip, rw_v, key, &data, &dlen);  if (r) return r;
+  return cht_cdb_donesomelookup(ip, rw_v, def, result, data, dlen,
+				cht_cdb_storeanswer_hb);
+}
+
+int cht_do_cdbtoplevel_cdb_wr(ClientData cd, Tcl_Interp *ip,
+			      const Cdbwr_SubCommand* subcmd,
+			      int objc, Tcl_Obj *const *objv) {
+  return subcmd->func((void*)subcmd,ip,objc,objv);
+}