piece-chain

commit 003fd961221b10fd75960257c508b107e252bb27
parent 0cec6d691981dbb10d2d0967dd0e3302eda34586
Author: gearsix <gearsix@tuta.io>
Date:   Sat,  9 Jul 2022 12:43:13 +0100

added buffree; fixed all memory leaks.

Diffstat:
M
buf.c
 | 
69
++++++++++++++++++++++++++++++++++++++++-----------------------------
M
buf.h
 | 
4
+++-
M
test.c
 | 
9
+++++++--

3 files changed, 50 insertions(+), 32 deletions(-)
diff --git a/buf.c b/buf.c
@@ -5,43 +5,44 @@
 #include <stdlib.h>
 #include <string.h>
 
-static const size_t blksiz = BUFSIZ/sizeof(Piece);
-static Piece **nextp = NULL;
+static Piece *pieceblk = NULL; /* block of all pieces */
+static Piece **freeblk = NULL; /* ptr block to all free'd `pieceblk` items */
 
-static size_t pfree(Piece *p)
+static void pclean()
+{
+	free(freeblk);
+	free(pieceblk);
+}
+
+static Piece *pfree(Piece *p)
 {
-	static Piece **freeblk = NULL;
 	static size_t nblk = 0, nfree = 0;
+	static const size_t blksiz = BUFSIZ/sizeof(Piece *);
 
-	if (!p) {
-		if (!nextp && nfree > 0)
-			nextp = &freeblk[--nfree];
-		return nfree;
-	}
+	if (!p) return (nfree == 0) ? NULL : freeblk[--nfree];
 
 	if (nfree + 1 > blksiz * nblk)
 		freeblk = realloc(freeblk, (++nblk * blksiz) * sizeof(Piece *));
 	if (!freeblk) { perror("failed to allocate freeblk"); exit(1); }
 
-	freeblk[nfree++] = p;
-	nextp = &freeblk[nfree - 1];
-	return nfree;
+	return freeblk[nfree++] = p;
 }
 
 static Piece *palloc()
 {
 	Piece *p;
-	static Piece *pieceblk = NULL;
-	static size_t nblk = 0, npieces = 0;
+	
+	static size_t nblk = 0, nalloc = 0;
+	static const size_t blksiz = BUFSIZ/sizeof(Piece);
 
-	if (pfree(NULL) > 0) {
-		p = *nextp;
-		nextp = NULL;
-	} else {
-		if (npieces + 1 > blksiz * nblk)
+	static int hook = 0;
+	if (hook == 0) { atexit(pclean); hook = 1; }
+
+	if ( !(p = pfree(NULL)) ) {
+		if (nalloc + 1 > blksiz * nblk)
 			pieceblk = realloc(pieceblk, (++nblk * blksiz) * sizeof(Piece));
 		if (!pieceblk) { perror("failed to allocate pieceblk"); exit(1); }
-		p = &pieceblk[npieces++];
+		p = &pieceblk[nalloc++];
 	}
 
 	return memset(p, 0, sizeof(Piece));
@@ -65,23 +66,33 @@ static Piece *psplit(Piece *p, long int offset)
 	return p;
 }
 
-struct Buf *bufinit(FILE *f)
+struct Buf *bufinit(FILE *read, FILE *append)
 {
 	Buf *b = calloc(1, sizeof(Buf));
 
-	b->append = tmpfile();
+	if (!read || !append) return NULL;
+	
+	b->read = read;
+	b->append = append;
+	
 	b->tail = b->pos = b->head = palloc();
-
-	if (f) {
-		b->read =f;
-		b->pos->f = b->read;
-		fseek(b->read, 0, SEEK_END);
-		b->size = b->pos->len = ftell(b->read);
-	}
+	b->pos->f = b->read;
+	fseek(b->read, 0, SEEK_END);
+	b->size = b->pos->len = ftell(b->read);
 
 	return b;
 }
 
+void buffree(Buf *b)
+{
+	Piece *p = b->tail->next;
+	while (p) {
+		pfree(p->prev);
+		p = p->next;
+	}
+	free(b);
+}
+
 Piece *bufidx(Buf *b, size_t pos)
 {
 	size_t idx = b->idx, offset;
diff --git a/buf.h b/buf.h
@@ -15,7 +15,9 @@ typedef struct Buf {
 	struct Piece *tail, *pos, *head;
 } Buf;
 
-Buf *bufinit(FILE *f);
+Buf *bufinit(FILE *read, FILE *append);
+
+void buffree(Buf *b);
 
 Piece *bufidx(Buf *b, size_t pos);
 
diff --git a/test.c b/test.c
@@ -1,5 +1,6 @@
 #include "buf.h"
 #include <stdio.h>
+#include <stdlib.h>
 #include <assert.h>
 #include <string.h>
 
@@ -9,7 +10,7 @@
 #define OUTBUF "hey buddy!" /* tests will aim to change INBUF to this */
 
 Buf *b;
-FILE *in, *out;
+FILE *in, *tmp, *out;
 
 void setup()
 {	
@@ -17,6 +18,8 @@ void setup()
 	if (ferror(in)) perror("fopen in.txt");
 	fputs(INBUF, in);
 
+	tmp = tmpfile();
+
 	out = fopen(OUTFILE, "w+b");
 	if (ferror(in)) perror("fopen out.txt");
 
@@ -25,8 +28,10 @@ void setup()
 
 void setdown()
 {
+	buffree(b);
 	fclose(out);
 	fclose(in);
+	fclose(tmp);
 }
 
 void print()
@@ -52,7 +57,7 @@ void test_bufinit()
 {
 	Piece *p;
 
-	b = bufinit(in);
+	b = bufinit(in, tmp);
 
 	assert(b->read);
 	assert(b->append);