From 7d2269b5aeb84c034196f83e855e1dfcbd837116 Mon Sep 17 00:00:00 2001
From: Markus Armbruster <armbru@pond.sub.org>
Date: Wed, 4 May 2011 07:45:05 +0200
Subject: [PATCH] Make ef_open() extend files with fixed size automatically

Turns the fixed size into an invariant.  Before, the files utility
created them empty, then extended them.
---
 src/lib/common/file.c | 77 +++++++++++++++++++++++++++----------------
 src/util/files.c      |  7 ----
 2 files changed, 49 insertions(+), 35 deletions(-)

diff --git a/src/lib/common/file.c b/src/lib/common/file.c
index d7fd63557..e586d96e0 100644
--- a/src/lib/common/file.c
+++ b/src/lib/common/file.c
@@ -58,6 +58,7 @@ static int do_write(struct empfile *, void *, int, int);
 static unsigned get_seqno(struct empfile *, int);
 static void new_seqno(struct empfile *, void *);
 static void must_be_fresh(struct empfile *, void *);
+static int do_extend(struct empfile *, int);
 static void do_blank(struct empfile *, void *, int, int);
 static int ef_check(int);
 
@@ -74,7 +75,7 @@ int
 ef_open(int type, int how)
 {
     struct empfile *ep;
-    int oflags, fd, fsiz, fids, nslots;
+    int oflags, fd, fsiz, fids, nslots, fail;
 
     if (ef_check(type) < 0)
 	return 0;
@@ -97,19 +98,23 @@ ef_open(int type, int how)
     }
 
     /* get file size */
-    fsiz = fsize(fd);
-    if (fsiz % ep->size) {
-	logerror("Can't open %s (file size not a multiple of record size %d)",
-		 ep->file, ep->size);
-	close(fd);
-	return 0;
-    }
-    fids = fsiz / ep->size;
-    if (ep->nent >= 0 && ep->nent != fids && !(how & EFF_CREATE)) {
-	logerror("Can't open %s (got %d records instead of %d)",
-		 ep->file, fids, ep->nent);
-	close(fd);
-	return 0;
+    if (how & EFF_CREATE) {
+	fids = ep->nent >= 0 ? ep->nent : 0;
+    } else {
+	fsiz = fsize(fd);
+	if (fsiz % ep->size) {
+	    logerror("Can't open %s (file size not a multiple of record size %d)",
+		     ep->file, ep->size);
+	    close(fd);
+	    return 0;
+	}
+	fids = fsiz / ep->size;
+	if (ep->nent >= 0 && ep->nent != fids) {
+	    logerror("Can't open %s (got %d records instead of %d)",
+		     ep->file, fids, ep->nent);
+	    close(fd);
+	    return 0;
+	}
     }
 
     /* allocate cache */
@@ -139,17 +144,24 @@ ef_open(int type, int how)
     }
     ep->baseid = 0;
     ep->cids = 0;
-    ep->fids = fids;
     ep->flags = (ep->flags & EFF_IMMUTABLE) | (how & ~EFF_CREATE);
     ep->fd = fd;
 
-    /* map file into cache */
-    if ((how & EFF_MEM) && fids) {
-	if (fillcache(ep, 0) != fids) {
-	    ep->cids = 0;	/* prevent cache flush */
-	    ef_close(type);
-	    return 0;
-	}
+    if (how & EFF_CREATE) {
+	/* populate new file */
+	ep->fids = 0;
+	fail = !do_extend(ep, fids);
+    } else {
+	ep->fids = fids;
+	if ((how & EFF_MEM) && fids)
+	    fail = fillcache(ep, 0) != fids;
+	else
+	    fail = 0;
+    }
+    if (fail) {
+	ep->cids = 0;	/* prevent cache flush */
+	ef_close(type);
+	return 0;
     }
 
     if (ep->onresize)
@@ -678,13 +690,24 @@ int
 ef_extend(int type, int count)
 {
     struct empfile *ep;
-    char *p;
-    int need_sentinel, i, id;
 
-    if (ef_check(type) < 0 || CANT_HAPPEN(EF_IS_VIEW(type)))
+    if (ef_check(type) < 0)
 	return 0;
     ep = &empfile[type];
-    if (CANT_HAPPEN(count < 0))
+    if (!do_extend(ep, count))
+	return 0;
+    if (ep->onresize)
+	ep->onresize(type);
+    return 1;
+}
+
+static int
+do_extend(struct empfile *ep, int count)
+{
+    char *p;
+    int need_sentinel, i, id;
+
+    if (CANT_HAPPEN(EF_IS_VIEW(ep->uid)) || count < 0)
 	return 0;
 
     id = ep->fids;
@@ -723,8 +746,6 @@ ef_extend(int type, int count)
 	}
     }
     ep->fids = id + count;
-    if (ep->onresize)
-	ep->onresize(type);
     return 1;
 }
 
diff --git a/src/util/files.c b/src/util/files.c
index 85fa7d630..10bf5d2fb 100644
--- a/src/util/files.c
+++ b/src/util/files.c
@@ -136,8 +136,6 @@ main(int argc, char *argv[])
 	}
     }
 
-    ef_extend(EF_GAME, 1);
-    ef_extend(EF_NATION, MAXNOC);
     ef_read(EF_NATION, 0, &nat);
     strcpy(nat.nat_cnam, "POGO");
     strcpy(nat.nat_pnam, "peter");
@@ -147,7 +145,6 @@ main(int argc, char *argv[])
     nat.nat_flags |= NF_FLASH;
     ef_write(EF_NATION, 0, &nat);
     printf("All praise to %s!\n", nat.nat_cnam);
-    ef_extend(EF_REALM, MAXNOC * MAXNOR);
     if (mkdir(teldir, S_IRWXU | S_IRWXG) < 0 && errno != EEXIST) {
 	perror(teldir);
 	printf("Can't make telegram directory\n");
@@ -159,10 +156,6 @@ main(int argc, char *argv[])
     }
     close(creat(annfil, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP));
 
-    ef_extend(EF_SECTOR, WORLD_SZ());
-    ef_extend(EF_MAP, MAXNOC);
-    ef_extend(EF_BMAP, MAXNOC);
-
     for (i = 0; i < EF_MAX; i++) {
 	if (!EF_IS_GAME_STATE(i))
 	    continue;
-- 
2.43.0