use zlib internally to decompress

1 files changed, 221 insertions, 0 deletions

diff --git a/src/io.c b/src/io.c
new file mode 100644
index 0000000..38a1b07
--- /dev/null
+++ b/src/io.c
@@ -0,0 +1,221 @@
+/* io.c - Alpine Package Keeper (APK)
+ *
+ * Copyright (C) 2005-2008 Natanael Copa <n@tanael.org>
+ * Copyright (C) 2008 Timo Teräs <timo.teras@iki.fi>
+ * All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it 
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation. See http://www.gnu.org/ for details.
+ */
+
+#include <stdio.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <malloc.h>
+
+#include "apk_defines.h"
+#include "apk_io.h"
+
+struct apk_fd_istream {
+	struct apk_istream is;
+	int fd;
+};
+
+static size_t fd_read(void *stream, void *ptr, size_t size)
+{
+	struct apk_fd_istream *fis =
+		container_of(stream, struct apk_fd_istream, is);
+	size_t i = 0, r;
+
+	if (ptr == NULL) {
+		if (lseek(fis->fd, size, SEEK_CUR) < 0)
+			return -1;
+		return size;
+	}
+
+	while (i < size) {
+		r = read(fis->fd, ptr + i, size - i);
+		if (r < 0)
+			return r;
+		if (r == 0)
+			return i;
+		i += r;
+	}
+
+	return i;
+}
+
+static size_t fd_splice(void *stream, int fd, size_t size)
+{
+	struct apk_fd_istream *fis =
+		container_of(stream, struct apk_fd_istream, is);
+	size_t i = 0, r;
+
+	while (i != size) {
+		r = splice(fis->fd, NULL, fd, NULL, size - i, SPLICE_F_MOVE);
+		if (r == -1)
+			return i;
+		i += r;
+	}
+
+	return i;
+}
+
+static void fd_close(void *stream)
+{
+	struct apk_fd_istream *fis =
+		container_of(stream, struct apk_fd_istream, is);
+
+	close(fis->fd);
+	free(fis);
+}
+
+struct apk_istream *apk_istream_from_fd(int fd)
+{
+	struct apk_fd_istream *fis;
+
+	fis = malloc(sizeof(struct apk_fd_istream));
+	if (fis == NULL)
+		return NULL;
+
+	*fis = (struct apk_fd_istream) {
+		.is.read = fd_read,
+		.is.splice = fd_splice,
+		.is.close = fd_close,
+		.fd = fd,
+	};
+
+	return &fis->is;
+}
+
+struct apk_istream *apk_istream_from_file(const char *file)
+{
+	int fd;
+
+	fd = open(file, O_RDONLY);
+	if (fd < 0)
+		return NULL;
+
+	return apk_istream_from_fd(fd);
+}
+
+size_t apk_istream_skip(struct apk_istream *is, size_t size)
+{
+	unsigned char buf[2048];
+	size_t done = 0, r, togo;
+
+	while (done < size) {
+		togo = size - done;
+		if (togo > sizeof(buf))
+			togo = sizeof(buf);
+		r = is->read(is, buf, togo);
+		if (r < 0)
+			return r;
+		done += r;
+		if (r != togo)
+			break;
+	}
+	return done;
+}
+
+size_t apk_istream_splice(void *stream, int fd, size_t size)
+{
+	struct apk_istream *is = (struct apk_istream *) stream;
+	unsigned char buf[2048];
+	size_t done = 0, r, togo;
+
+	while (done < size) {
+		togo = size - done;
+		if (togo > sizeof(buf))
+			togo = sizeof(buf);
+		r = is->read(is, buf, togo);
+		if (r < 0)
+			return r;
+		if (write(fd, buf, r) != r)
+			return -1;
+		done += r;
+		if (r != togo)
+			break;
+	}
+	return done;
+}
+
+struct apk_istream_bstream {
+	struct apk_bstream bs;
+	struct apk_istream *is;
+	csum_ctx_t csum_ctx;
+	unsigned char buffer[8*1024];
+};
+
+static size_t is_bs_read(void *stream, void **ptr)
+{
+	struct apk_istream_bstream *isbs =
+		container_of(stream, struct apk_istream_bstream, bs);
+	size_t size;
+
+	size = isbs->is->read(isbs->is, isbs->buffer, sizeof(isbs->buffer));
+	if (size <= 0)
+		return size;
+
+	csum_process(&isbs->csum_ctx, isbs->buffer, size);
+
+	*ptr = isbs->buffer;
+	return size;
+}
+
+static void is_bs_close(void *stream, csum_t csum)
+{
+	struct apk_istream_bstream *isbs =
+		container_of(stream, struct apk_istream_bstream, bs);
+
+	if (csum != NULL)
+		csum_finish(&isbs->csum_ctx, csum);
+
+	isbs->is->close(isbs->is);
+	free(isbs);
+}
+struct apk_bstream *apk_bstream_from_istream(struct apk_istream *istream)
+{
+	struct apk_istream_bstream *isbs;
+
+	isbs = malloc(sizeof(struct apk_istream_bstream));
+	if (isbs == NULL)
+		return NULL;
+
+	isbs->bs = (struct apk_bstream) {
+		.read = is_bs_read,
+		.close = is_bs_close,
+	};
+	isbs->is = istream;
+	csum_init(&isbs->csum_ctx);
+
+	return &isbs->bs;
+}
+
+struct apk_bstream *apk_bstream_from_fd(int fd)
+{
+	/* FIXME: Write mmap based bstream for files */
+	return apk_bstream_from_istream(apk_istream_from_fd(fd));
+}
+
+apk_blob_t apk_blob_from_istream(struct apk_istream *is, size_t size)
+{
+	void *ptr;
+	size_t rsize;
+
+	ptr = malloc(size);
+	if (ptr == NULL)
+		return APK_BLOB_NULL;
+
+	rsize = is->read(is, ptr, size);
+	if (rsize < 0) {
+		free(ptr);
+		return APK_BLOB_NULL;
+	}
+	if (rsize != size)
+		ptr = realloc(ptr, rsize);
+
+	return APK_BLOB_PTR_LEN(ptr, rsize);
+}
+