From 8af4ee6f415fe316894e4423235dfc4ee70d8cbb Mon Sep 17 00:00:00 2001
From: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
Date: Sun, 4 Jun 2023 15:40:29 +0200
Subject: libio: move splice function from ostream to istream

It touches internals of the istream, particularly the buffer, but
not of the ostream. It really belongs to istream_t.

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
---
 bin/tar2sqfs/src/process_tarball.c |  2 +-
 include/io/istream.h               | 16 ++++++++++++++++
 include/io/ostream.h               | 17 -----------------
 lib/io/src/istream.c               | 32 ++++++++++++++++++++++++++++++++
 lib/io/src/ostream.c               | 33 ---------------------------------
 lib/io/test/stream_splice.c        |  2 +-
 6 files changed, 50 insertions(+), 52 deletions(-)

diff --git a/bin/tar2sqfs/src/process_tarball.c b/bin/tar2sqfs/src/process_tarball.c
index ef49d20..76c7dc1 100644
--- a/bin/tar2sqfs/src/process_tarball.c
+++ b/bin/tar2sqfs/src/process_tarball.c
@@ -28,7 +28,7 @@ static int write_file(sqfs_writer_t *sqfs, dir_iterator_t *it,
 	}
 
 	do {
-		ret = ostream_append_from_istream(out, in, cfg.block_size);
+		ret = istream_splice(in, out, cfg.block_size);
 	} while (ret > 0);
 
 	ostream_flush(out);
diff --git a/include/io/istream.h b/include/io/istream.h
index 9c34678..7adb204 100644
--- a/include/io/istream.h
+++ b/include/io/istream.h
@@ -8,6 +8,7 @@
 #define IO_ISTREAM_H
 
 #include "sqfs/predef.h"
+#include "io/ostream.h"
 
 /**
  * @struct istream_t
@@ -127,6 +128,21 @@ SQFS_INLINE const char *istream_get_filename(istream_t *strm)
  */
 SQFS_INTERNAL int istream_skip(istream_t *strm, sqfs_u64 size);
 
+/**
+ * @brief Dump data from an input stream to an output stream
+ *
+ * @memberof istream_t
+ *
+ * @param in A pointer to an input stream to read from.
+ * @param out A pointer to an output stream to append to.
+ * @param size The number of bytes to copy over.
+ *
+ * @return The number of bytes copied on success, -1 on failure,
+ *         0 on end-of-file.
+ */
+SQFS_INTERNAL sqfs_s32 istream_splice(istream_t *in, ostream_t *out,
+				      sqfs_u32 size);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/include/io/ostream.h b/include/io/ostream.h
index c1602ab..9cc37ad 100644
--- a/include/io/ostream.h
+++ b/include/io/ostream.h
@@ -8,7 +8,6 @@
 #define IO_OSTREAM_H
 
 #include "sqfs/predef.h"
-#include "io/istream.h"
 
 /**
  * @struct ostream_t
@@ -104,22 +103,6 @@ SQFS_INLINE const char *ostream_get_filename(ostream_t *strm)
 	return strm->get_filename(strm);
 }
 
-/**
- * @brief Read data from an input stream and append it to an output stream
- *
- * @memberof ostream_t
- *
- * @param out A pointer to an output stream to append to.
- * @param in A pointer to an input stream to read from.
- * @param size The number of bytes to copy over.
- *
- * @return The number of bytes copied on success, -1 on failure,
- *         0 on end-of-file.
- */
-SQFS_INTERNAL sqfs_s32 ostream_append_from_istream(ostream_t *out,
-						   istream_t *in,
-						   sqfs_u32 size);
-
 #ifdef __cplusplus
 }
 #endif
diff --git a/lib/io/src/istream.c b/lib/io/src/istream.c
index 051fac8..2b89a00 100644
--- a/lib/io/src/istream.c
+++ b/lib/io/src/istream.c
@@ -64,3 +64,35 @@ int istream_skip(istream_t *strm, sqfs_u64 size)
 
 	return 0;
 }
+
+sqfs_s32 istream_splice(istream_t *in, ostream_t *out, sqfs_u32 size)
+{
+	sqfs_s32 total = 0;
+	size_t diff;
+
+	if (size > 0x7FFFFFFF)
+		size = 0x7FFFFFFF;
+
+	while (size > 0) {
+		if (in->buffer_offset >= in->buffer_used) {
+			if (istream_precache(in))
+				return -1;
+
+			if (in->buffer_used == 0)
+				break;
+		}
+
+		diff = in->buffer_used - in->buffer_offset;
+		if (diff > size)
+			diff = size;
+
+		if (ostream_append(out, in->buffer + in->buffer_offset, diff))
+			return -1;
+
+		in->buffer_offset += diff;
+		size -= diff;
+		total += diff;
+	}
+
+	return total;
+}
diff --git a/lib/io/src/ostream.c b/lib/io/src/ostream.c
index da0b7b3..35f98d4 100644
--- a/lib/io/src/ostream.c
+++ b/lib/io/src/ostream.c
@@ -33,36 +33,3 @@ int ostream_append_sparse(ostream_t *strm, size_t size)
 
 	return strm->append_sparse(strm, size);
 }
-
-sqfs_s32 ostream_append_from_istream(ostream_t *out, istream_t *in,
-				     sqfs_u32 size)
-{
-	sqfs_s32 total = 0;
-	size_t diff;
-
-	if (size > 0x7FFFFFFF)
-		size = 0x7FFFFFFF;
-
-	while (size > 0) {
-		if (in->buffer_offset >= in->buffer_used) {
-			if (istream_precache(in))
-				return -1;
-
-			if (in->buffer_used == 0)
-				break;
-		}
-
-		diff = in->buffer_used - in->buffer_offset;
-		if (diff > size)
-			diff = size;
-
-		if (out->append(out, in->buffer + in->buffer_offset, diff))
-			return -1;
-
-		in->buffer_offset += diff;
-		size -= diff;
-		total += diff;
-	}
-
-	return total;
-}
diff --git a/lib/io/test/stream_splice.c b/lib/io/test/stream_splice.c
index 5379b39..9008d83 100644
--- a/lib/io/test/stream_splice.c
+++ b/lib/io/test/stream_splice.c
@@ -79,7 +79,7 @@ int main(int argc, char **argv)
 	TEST_NOT_NULL(in);
 
 	for (;;) {
-		ret = ostream_append_from_istream(&out, in, 211);
+		ret = istream_splice(in, &out, 211);
 		TEST_ASSERT(ret >= 0);
 
 		if (ret == 0)
-- 
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