Adding upstream version 3.4.23.upstream/3.4.23upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 110 insertions, 0 deletions

diff --git a/src/util/vbuf.h b/src/util/vbuf.h
new file mode 100644
index 0000000..149fe0c
--- /dev/null
+++ b/src/util/vbuf.h
@@ -0,0 +1,110 @@
+#ifndef _VBUF_H_INCLUDED_
+#define _VBUF_H_INCLUDED_
+
+/*++
+/* NAME
+/*	vbuf 3h
+/* SUMMARY
+/*	generic buffer
+/* SYNOPSIS
+/*	#include <vbuf.h>
+/* DESCRIPTION
+/* .nf
+
+ /*
+  * The VBUF buffer is defined by 1) its structure, by 2) the VBUF_GET() and
+  * 3) VBUF_PUT() operations that automatically handle buffer empty and
+  * buffer full conditions, and 4) by the VBUF_SPACE() operation that allows
+  * the user to reserve buffer space ahead of time, to allow for situations
+  * where calling VBUF_PUT() is not possible or desirable.
+  *
+  * The VBUF buffer does not specify primitives for memory allocation or
+  * deallocation. The purpose is to allow different applications to have
+  * different strategies: a memory-resident buffer; a memory-mapped file; or
+  * a stdio-like window to an open file. Each application provides its own
+  * get(), put() and space() methods that perform the necessary magic.
+  *
+  * This interface is pretty normal. With one exception: the number of bytes
+  * left to read is negated. This is done so that we can change direction
+  * between reading and writing on the fly. The alternative would be to use
+  * separate read and write counters per buffer.
+  */
+typedef struct VBUF VBUF;
+typedef int (*VBUF_GET_READY_FN) (VBUF *);
+typedef int (*VBUF_PUT_READY_FN) (VBUF *);
+typedef int (*VBUF_SPACE_FN) (VBUF *, ssize_t);
+
+struct VBUF {
+    int     flags;			/* status, see below */
+    unsigned char *data;		/* variable-length buffer */
+    ssize_t len;			/* buffer length */
+    ssize_t cnt;			/* bytes left to read/write */
+    unsigned char *ptr;			/* read/write position */
+    VBUF_GET_READY_FN get_ready;	/* read buffer empty action */
+    VBUF_PUT_READY_FN put_ready;	/* write buffer full action */
+    VBUF_SPACE_FN space;		/* request for buffer space */
+};
+
+ /*
+  * Typically, an application will embed a VBUF structure into a larger
+  * structure that also contains application-specific members. This approach
+  * gives us the best of both worlds. The application can still use the
+  * generic VBUF primitives for reading and writing VBUFs. The macro below
+  * transforms a pointer from VBUF structure to the structure that contains
+  * it.
+  */
+#define VBUF_TO_APPL(vbuf_ptr,app_type,vbuf_member) \
+    ((app_type *) (((char *) (vbuf_ptr)) - offsetof(app_type,vbuf_member)))
+
+ /*
+  * Buffer status management.
+  */
+#define VBUF_FLAG_RD_ERR	(1<<0)	/* read error */
+#define VBUF_FLAG_WR_ERR	(1<<1)	/* write error */
+#define VBUF_FLAG_ERR		(VBUF_FLAG_RD_ERR | VBUF_FLAG_WR_ERR)
+#define VBUF_FLAG_EOF		(1<<2)	/* end of data */
+#define VBUF_FLAG_RD_TIMEOUT	(1<<3)	/* read timeout */
+#define VBUF_FLAG_WR_TIMEOUT	(1<<4)	/* write timeout */
+#define VBUF_FLAG_TIMEOUT	(VBUF_FLAG_RD_TIMEOUT | VBUF_FLAG_WR_TIMEOUT)
+#define VBUF_FLAG_BAD	(VBUF_FLAG_ERR | VBUF_FLAG_EOF | VBUF_FLAG_TIMEOUT)
+#define VBUF_FLAG_FIXED		(1<<5)	/* fixed-size buffer */
+
+#define vbuf_rd_error(v) ((v)->flags & (VBUF_FLAG_RD_ERR | VBUF_FLAG_RD_TIMEOUT))
+#define vbuf_wr_error(v) ((v)->flags & (VBUF_FLAG_WR_ERR | VBUF_FLAG_WR_TIMEOUT))
+#define vbuf_rd_timeout(v)	((v)->flags & VBUF_FLAG_RD_TIMEOUT)
+#define vbuf_wr_timeout(v)	((v)->flags & VBUF_FLAG_WR_TIMEOUT)
+
+#define vbuf_error(v)	((v)->flags & (VBUF_FLAG_ERR | VBUF_FLAG_TIMEOUT))
+#define vbuf_eof(v)	((v)->flags & VBUF_FLAG_EOF)
+#define vbuf_timeout(v)	((v)->flags & VBUF_FLAG_TIMEOUT)
+#define vbuf_clearerr(v) ((v)->flags &= ~VBUF_FLAG_BAD)
+
+ /*
+  * Buffer I/O-like operations and results.
+  */
+#define VBUF_GET(v)	((v)->cnt < 0 ? ++(v)->cnt, \
+				(int) *(v)->ptr++ : vbuf_get(v))
+#define VBUF_PUT(v,c)	((v)->cnt > 0 ? --(v)->cnt, \
+				(int) (*(v)->ptr++ = (c)) : vbuf_put((v),(c)))
+#define VBUF_SPACE(v,n) ((v)->space((v),(n)))
+
+#define VBUF_EOF	(-1)		/* no more space or data */
+
+extern int vbuf_get(VBUF *);
+extern int vbuf_put(VBUF *, int);
+extern int vbuf_unget(VBUF *, int);
+extern ssize_t vbuf_read(VBUF *, void *, ssize_t);
+extern ssize_t vbuf_write(VBUF *, const void *, ssize_t);
+
+/* LICENSE
+/* .ad
+/* .fi
+/*	The Secure Mailer license must be distributed with this software.
+/* AUTHOR(S)
+/*	Wietse Venema
+/*	IBM T.J. Watson Research
+/*	P.O. Box 704
+/*	Yorktown Heights, NY 10598, USA
+/*--*/
+
+#endif