dovecot-2.2: liblib: Added istream-hash, similar to ostream-hash.

[dovecot at dovecot.org]

details:   http://hg.dovecot.org/dovecot-2.2/rev/f73c388ad360
changeset: 16720:f73c388ad360
user:      Timo Sirainen <tss at iki.fi>
date:      Mon Sep 09 04:34:58 2013 +0300
description:
liblib: Added istream-hash, similar to ostream-hash.

diffstat:

 src/lib/Makefile.am    |   2 +
 src/lib/istream-hash.c |  60 ++++++++++++++++++++++++++++++++++++++++++++++++++
 src/lib/istream-hash.h |  12 ++++++++++
 3 files changed, 74 insertions(+), 0 deletions(-)

diffs (99 lines):

diff -r 63edc752479d -r f73c388ad360 src/lib/Makefile.am
--- a/src/lib/Makefile.am	Mon Sep 09 04:34:45 2013 +0300
+++ b/src/lib/Makefile.am	Mon Sep 09 04:34:58 2013 +0300
@@ -62,6 +62,7 @@
 	istream-crlf.c \
 	istream-data.c \
 	istream-file.c \
+	istream-hash.c \
 	istream-jsonstr.c \
 	istream-limit.c \
 	istream-mmap.c \
@@ -189,6 +190,7 @@
 	istream-chain.h \
 	istream-concat.h \
 	istream-crlf.h \
+	istream-hash.h \
 	istream-jsonstr.h \
 	istream-private.h \
 	istream-rawlog.h \
diff -r 63edc752479d -r f73c388ad360 src/lib/istream-hash.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/lib/istream-hash.c	Mon Sep 09 04:34:58 2013 +0300
@@ -0,0 +1,60 @@
+/* Copyright (c) 2013 Dovecot authors, see the included COPYING file */
+
+#include "lib.h"
+#include "hash-method.h"
+#include "istream-private.h"
+#include "istream-hash.h"
+
+struct hash_istream {
+	struct istream_private istream;
+
+	const struct hash_method *method;
+	void *hash_context;
+};
+
+static ssize_t
+i_stream_hash_read(struct istream_private *stream)
+{
+	struct hash_istream *hstream = (struct hash_istream *)stream;
+	const unsigned char *data;
+	size_t size;
+	ssize_t ret;
+
+	i_stream_seek(stream->parent, stream->parent_start_offset +
+		      stream->istream.v_offset);
+
+	ret = i_stream_read_copy_from_parent(&stream->istream);
+	if (ret > 0 && hstream->hash_context != NULL) {
+		data = i_stream_get_data(&stream->istream, &size);
+		i_assert((size_t)ret <= size);
+		hstream->method->loop(hstream->hash_context,
+				      data+(size-ret), ret);
+	} else if (ret < 0) {
+		/* we finished hashing it. don't access it anymore, because
+		   the memory pointed by the hash may be freed before the
+		   istream itself */
+		hstream->hash_context = NULL;
+	}
+	return ret;
+}
+
+struct istream *
+i_stream_create_hash(struct istream *input, const struct hash_method *method,
+		     void *hash_context)
+{
+	struct hash_istream *hstream;
+
+	hstream = i_new(struct hash_istream, 1);
+	hstream->istream.max_buffer_size = input->real_stream->max_buffer_size;
+	hstream->istream.stream_size_passthrough = TRUE;
+
+	hstream->istream.read = i_stream_hash_read;
+
+	hstream->istream.istream.blocking = input->blocking;
+	hstream->istream.istream.seekable = FALSE;
+
+	hstream->method = method;
+	hstream->hash_context = hash_context;
+	return i_stream_create(&hstream->istream, input,
+			       i_stream_get_fd(input));
+}
diff -r 63edc752479d -r f73c388ad360 src/lib/istream-hash.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/lib/istream-hash.h	Mon Sep 09 04:34:58 2013 +0300
@@ -0,0 +1,12 @@
+#ifndef ISTREAM_HASH_H
+#define ISTREAM_HASH_H
+
+struct hash_method;
+
+/* hash_context must be allocated and initialized by caller. This istream will
+   simply call method->loop() for all the data going through the istream. */
+struct istream *
+i_stream_create_hash(struct istream *input, const struct hash_method *method,
+		     void *hash_context);
+
+#endif