Re: First cut at git port to Cygwin

From

Johannes Schindelin <johannes.schindelin@gmx.de>

Date

Oct 8, 2005, 22:06 UTC

Message-ID

<Pine.LNX.4.63.0510090004370.30110@wbgn013.biozentrum.uni-wuerzburg.de>

In-Reply-To

<7vk6gnpvf9.fsf@assigned-by-dhcp.cox.net>

Hi,

On Sat, 8 Oct 2005, Junio C Hamano wrote:

> Johannes Schindelin <Johannes.Schindelin@gmx.de> writes:
> 
> > Sure. Something like this?
> 
> Not, really.  What I meant was to rip out the writing out
> altogether, and perhaps making sure that the caller never calls
> us without MAP_PRIVATE.

How about this, then?

[PATCH] If NO_MMAP is defined, fake mmap() and munmap()

Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>

---

 Makefile      |    6 ++++++
 cache.h       |   16 ++++++++++++++++
 compat/mmap.c |   51 +++++++++++++++++++++++++++++++++++++++++++++++++++
 mailsplit.c   |    1 -
 4 files changed, 73 insertions(+), 1 deletions(-)
 create mode 100644 compat/mmap.c

diff --git a/Makefile b/Makefile
index 1bdf4de..7ca77cf 100644
--- a/Makefile
+++ b/Makefile
@@ -27,6 +27,8 @@
 # Define NEEDS_SOCKET if linking with libc is not enough (SunOS,
 # Patrick Mauritz).
 #
+# Define NO_MMAP if you want to avoid mmap.
+#
 # Define WITH_OWN_SUBPROCESS_PY if you want to use with python 2.3.
 #
 # Define NO_IPV6 if you lack IPv6 support and getaddrinfo().
@@ -258,6 +260,10 @@ ifdef NO_STRCASESTR
 	DEFINES += -Dstrcasestr=gitstrcasestr
 	LIB_OBJS += compat/strcasestr.o
 endif
+ifdef NO_MMAP
+	DEFINES += -Dmmap=gitfakemmap -Dmunmap=gitfakemunmap -DNO_MMAP
+	LIB_OBJS += compat/mmap.o
+endif
 ifdef NO_IPV6
 	DEFINES += -DNO_IPV6 -Dsockaddr_storage=sockaddr_in
 endif
diff --git a/cache.h b/cache.h
index 514adb8..5987d4c 100644
--- a/cache.h
+++ b/cache.h
@@ -11,7 +11,9 @@
 #include <string.h>
 #include <errno.h>
 #include <limits.h>
+#ifndef NO_MMAP
 #include <sys/mman.h>
+#endif
 #include <sys/param.h>
 #include <netinet/in.h>
 #include <sys/types.h>
@@ -356,4 +358,18 @@ extern void packed_object_info_detail(st
 /* Dumb servers support */
 extern int update_server_info(int);
 
+#ifdef NO_MMAP
+
+#ifndef PROT_READ
+#define PROT_READ 1
+#define PROT_WRITE 2
+#define MAP_PRIVATE 1
+#define MAP_FAILED ((void*)-1)
+#endif
+
+extern void *gitfakemmap(void *start, size_t length, int prot , int flags, int fd, off_t offset);
+extern int gitfakemunmap(void *start, size_t length);
+
+#endif
+
 #endif /* CACHE_H */
diff --git a/compat/mmap.c b/compat/mmap.c
new file mode 100644
index 0000000..3f035a0
--- /dev/null
+++ b/compat/mmap.c
@@ -0,0 +1,51 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include "../cache.h"
+
+void *gitfakemmap(void *start, size_t length, int prot , int flags, int fd, off_t offset)
+{
+	int n = 0;
+
+	if(start != NULL || !(flags & MAP_PRIVATE))
+		die("Invalid usage of gitfakemmap.");
+
+	if(lseek(fd, offset, SEEK_SET)<0) {
+		errno = EINVAL;
+		return MAP_FAILED;
+	}
+
+	start = xmalloc(length);
+	if(start == NULL) {
+		errno = ENOMEM;
+		return MAP_FAILED;
+	}
+
+	while(n < length) {
+		int count = read(fd, start+n, length-n);
+
+		if(count == 0) {
+			memset(start+n, 0, length-n);
+			break;
+		}
+
+		if(count < 0) {
+			free(start);
+			errno = EACCES;
+			return MAP_FAILED;
+		}
+
+		n += count;
+	}
+
+	return start;
+}
+
+int gitfakemunmap(void *start, size_t length)
+{
+	free(start);
+
+	return 0;
+}
+
diff --git a/mailsplit.c b/mailsplit.c
index 7981f87..0f8100d 100644
--- a/mailsplit.c
+++ b/mailsplit.c
@@ -9,7 +9,6 @@
 #include <fcntl.h>
 #include <sys/types.h>
 #include <sys/stat.h>
-#include <sys/mman.h>
 #include <string.h>
 #include <stdio.h>
 #include <ctype.h>
---
0.99.8.GIT