move readfile implementation to cache.

Reading and entire file in is only done for caching, uncached streams
will never do that, so it makes sense to move it from stream function
collection to cache functions, making it static along the way.

Signed-off-by: Gediminas Jakutis <gediminas@varciai.lt>

1 files changed, 37 insertions, 1 deletions

diff --git a/src/cache.c b/src/cache.c
index e0852f4..f158e44 100644
--- a/src/cache.c
+++ b/src/cache.c
@@ -2,6 +2,7 @@
 
 /* Copyright (C) 2020-2021 Gediminas Jakutis */
 
+#include <unistd.h>
 #include <errno.h>
 #include <stdlib.h>
 #include <string.h>
@@ -11,6 +12,8 @@
 #include "stream.h"
 #include "cache.h"
 
+static int cache_readfile(struct stream * const in);
+
 int cache_create(struct stream * const in)
 {
 	int ret = 0;
@@ -48,7 +51,7 @@ int cache_populate(struct stream * const in)
 			}
 		}
 	} else if (in->type == stream_in) {
-		try_s((ret == stream_readfile(in)), err);
+		try_s((ret == cache_readfile(in)), err);
 	} else {
 		try(1, err, EINVAL, "cannot populate a non-reading stream cache");
 	}
@@ -247,3 +250,36 @@ int cache_rewind(struct stream * const in)
 
 	return ret;
 }
+
+static int cache_readfile(struct stream * const in)
+{
+	ssize_t ret = 0;
+	size_t remaining = in->n * in->settings->stride;
+	ssize_t bytesread = 0;
+	size_t i;
+
+	try(in->fd < 3, err, EINVAL, "no file open for reading");
+
+	do {
+		ret = read(in->fd, in->cache + bytesread, remaining);
+		if (ret < 0) {
+			try(errno != EAGAIN, err, errno, "Writing to stream failed with %zi", ret);
+		} else {
+			bytesread += ret;
+			remaining -= ret;
+		}
+	} while (ret);
+
+	/* if this is a list, we need to adjust the link pointers from file offsets
+	 * to buffer addresses. 'Cept for the last one, which needs to be NULL.
+	 */
+	if (in->settings->format == list) {
+		for (i = 0; i < (in->n - 1); ++i) {
+			in->cache_l[i].nextaddr = in->cache + in->cache_l[i].offset;
+		}
+		in->cnode = in->cache_l;
+	}
+
+err:
+	return ret;
+}