From fcc49648fd74a07c50a9b0f8eab0b4aa64bab6ed Mon Sep 17 00:00:00 2001
From: ewt <devnull@localhost>
Date: Tue, 19 Dec 1995 16:17:39 +0000
Subject: [PATCH] Added routines for traversal

CVS patchset: 60
CVS date: 1995/12/19 16:17:39
---
 lib/falloc.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++--
 lib/falloc.h |  7 +++++++
 2 files changed, 55 insertions(+), 2 deletions(-)

diff --git a/lib/falloc.c b/lib/falloc.c
index 3f6ac14..cda0d77 100644
--- a/lib/falloc.c
+++ b/lib/falloc.c
@@ -51,8 +51,10 @@ faFile faOpen(char * path, int flags, int perms) {
 	    return NULL;
 	}
 	fas.firstFree = 0;
+	fas.fileSize = sizeof(newHdr);
     }
     else {
+	lseek(fas.fd, 0, SEEK_SET);
 	if (read(fas.fd, &newHdr, sizeof(newHdr)) != sizeof(newHdr)) {
 	    close(fas.fd);
 	    return NULL;
@@ -62,6 +64,13 @@ faFile faOpen(char * path, int flags, int perms) {
 	    return NULL;
 	}
 	fas.firstFree = newHdr.firstFree;
+
+	if (lseek(fas.fd, 0, SEEK_END) < 0) {
+	    close(fas.fd);
+	    return NULL;
+	}
+	
+	fas.fileSize = lseek(fas.fd, 0, SEEK_CUR);
     }
 
     fa = malloc(sizeof(*fa));
@@ -170,8 +179,7 @@ unsigned int faAlloc(faFile fa, unsigned int size) { /* returns 0 on failure */
 	char * space;
 
 	/* make a new block */
-	if (lseek(fa->fd, 0, SEEK_END) < 0) return 0;
-	newBlock = lseek(fa->fd, 0, SEEK_CUR);
+	newBlock = fa->fileSize;
 
 	space = calloc(1, size);
 	if (!space) return 0;
@@ -189,6 +197,8 @@ unsigned int faAlloc(faFile fa, unsigned int size) { /* returns 0 on failure */
 	    return 0;
 	}
 	free(space);
+
+	fa->fileSize += sizeof(block) + size;
     }
     
     return newBlock + sizeof(block); 
@@ -200,3 +210,39 @@ void faClose(faFile fa) {
     close(fa->fd);
     free(fa);
 }
+
+unsigned int faFirstOffset(faFile fa) {
+    return faNextOffset(fa, 0);
+}
+
+unsigned int faNextOffset(faFile fa, unsigned int lastOffset) {
+    struct faBlock block;
+    int offset;
+    int useBlock;
+
+    if (lastOffset) {
+	offset = lastOffset - sizeof(block);
+	useBlock = 0;
+    } else {
+	offset = sizeof(struct faFileHeader);
+	useBlock = 1;
+    }
+
+    block.isFree = 1;
+    while (offset < fa->fileSize && block.isFree) {
+	lseek(fa->fd, offset, SEEK_SET);
+	if (read(fa->fd, &block, sizeof(block)) != sizeof(block)) {
+	    return 0;
+	}
+
+	if (useBlock && !block.isFree) break;
+	useBlock = 1;
+
+	offset += sizeof(block) + block.size;
+    }
+
+    if (offset < fa->fileSize)
+	return (offset + sizeof(block));
+    else
+	return 0;
+}
diff --git a/lib/falloc.h b/lib/falloc.h
index c633999..49c2add 100644
--- a/lib/falloc.h
+++ b/lib/falloc.h
@@ -9,12 +9,19 @@ typedef struct faFile_s {
     int fd;
     int readOnly;
     unsigned int firstFree;
+    unsigned long fileSize;
 } * faFile;
 
+struct FaPlace_s;
+typedef struct FaPlace * faPlace;
+
 /* flags here is the same as for open(2) - NULL returned on error */
 faFile faOpen(char * path, int flags, int perms);
 unsigned int faAlloc(faFile fa, unsigned int size); /* returns 0 on failure */
 void faFree(faFile fa, unsigned int offset);
 void faClose(faFile fa);
 
+unsigned int faFirstOffset(faFile fa);
+unsigned int faNextOffset(faFile fa, unsigned int lastOffset);  /* 0 at end */
+
 #endif H_FALLOC
-- 
2.7.4