place ssdeep_context on the heap

When publishing an API based on ssdeep_context this enables us to change
its size without breaking API or ABI. Also splint appears to cope better
with that.

1 files changed, 19 insertions, 13 deletions

diff --git a/fuzzy.c b/fuzzy.c
index b530e92..71dedf2 100644
--- a/fuzzy.c
+++ b/fuzzy.c
@@ -122,10 +122,15 @@ struct ssdeep_context {
 	struct roll_state roll;
 };
 
-static int ssdeep_init(/*@out@*/ struct ssdeep_context *self) {
+static /*@only@*/ /*@null@*/ struct ssdeep_context *ssdeep_new(void) {
+	struct ssdeep_context *self;
+	if(NULL == (self = malloc(sizeof(struct ssdeep_context))))
+		return NULL;
 	self->blockhashes = malloc(sizeof(struct blockhash_context));
-	if(NULL == self->blockhashes)
-		return -1;
+	if(NULL == self->blockhashes) {
+		free(self);
+		return NULL;
+	}
 	self->start_blocksize = MIN_BLOCKSIZE;
 	self->blockhashes->h = HASH_INIT;
 	self->blockhashes->halfh = HASH_INIT;
@@ -133,7 +138,7 @@ static int ssdeep_init(/*@out@*/ struct ssdeep_context *self) {
 	self->blockhashes->next = NULL;
 	self->total_size = 0;
 	roll_init(&self->roll);
-	return 0;
+	return self;
 }
 
 static void ssdeep_try_reduce_blockhash(struct ssdeep_context *self) {
@@ -293,7 +298,7 @@ static void ssdeep_digest(const struct ssdeep_context *self,
 	*result = '\0';
 }
 
-static void ssdeep_clear(struct ssdeep_context *self) {
+static void ssdeep_free(/*@only@*/ struct ssdeep_context *self) {
 	struct blockhash_context *bh, *bhn;
 	bh = self->blockhashes;
 	while(bh) {
@@ -301,27 +306,28 @@ static void ssdeep_clear(struct ssdeep_context *self) {
 		free(bh);
 		bh = bhn;
 	}
+	free(self);
 }
 
 int fuzzy_hash_buf(const unsigned char *buf, uint32_t buf_len,
 		/*@out@*/ char *result) {
-	struct ssdeep_context ctx[1];
-	if(ssdeep_init(ctx) < 0)
+	struct ssdeep_context *ctx;
+	if(NULL == (ctx = ssdeep_new()))
 		return -1;
 	if(ssdeep_engine(ctx, buf, buf_len) < 0) {
-		ssdeep_clear(ctx);
+		ssdeep_free(ctx);
 		return -1;
 	}
 	ssdeep_digest(ctx, result);
-	ssdeep_clear(ctx);
+	ssdeep_free(ctx);
 	return 0;
 }
 
 int fuzzy_hash_stream(FILE *handle, /*@out@*/ char *result) {
-	struct ssdeep_context ctx[1];
+	struct ssdeep_context *ctx;
 	unsigned char buffer[4096];
 	size_t n;
-	if(ssdeep_init(ctx) < 0)
+	if(NULL == (ctx = ssdeep_new()))
 		return -1;
 	for(;;) {
 		n = fread(buffer, 1, 4096, handle);
@@ -333,10 +339,10 @@ int fuzzy_hash_stream(FILE *handle, /*@out@*/ char *result) {
 	if(ferror(handle) != 0)
 		goto errout;
 	ssdeep_digest(ctx, result);
-	ssdeep_clear(ctx);
+	ssdeep_free(ctx);
 	return 0;
 errout:
-	ssdeep_clear(ctx);
+	ssdeep_free(ctx);
 	return -1;
 }