Re: htonll, ntohll

2013-11-13 Thread Andreas Ericsson 

On 2013-11-05 01:00, Ramsay Jones wrote:


[Note: I have never particularly liked htons, htonl et.al., so adding
these htonll/ntohll functions doesn't thrill me! :-D For example see
this post[1], which echo's my sentiments exactly.]



That post actually contradicts your statement, as it clearly states
that someone at Adobe figured out about byte order and there would
have been no problems transferring files between (big-endian and
little-endian) machines... if the people at Adobe wrote proper code
to encode and decode their files.

htonl(), ntohl(), htons(), ntohs() are those encode and decode
functions. If you or the author of the post you linked think otherwise,
you're misinformed and need to learn what encoding and decoding means.

--
Andreas Ericsson   andreas.erics...@op5.se
OP5 AB www.op5.se
Tel: +46 8-230225  Fax: +46 8-230231

Considering the successes of the wars on alcohol, poverty, drugs and
terror, I think we should give some serious thought to declaring war
on peace.
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Re: htonll, ntohll

2013-11-12 Thread Jakub Narębski 

W dniu 2013-11-05 01:00, Ramsay Jones pisze:


[Note: I have never particularly liked htons, htonl et.al., so adding
these htonll/ntohll functions doesn't thrill me! :-D For example see
this post[1], which echo's my sentiments exactly.]

HTH

ATB,
Ramsay Jones

[1] http://commandcenter.blogspot.co.uk/2012/04/byte-order-fallacy.html


Errr... htonl is about host to network order, and not about big- or
little-endianness of architecture.  The macros are good, its their
implementation that might fail [1].

--
Jakub Narębski

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Re: htonll, ntohll

2013-11-06 Thread Torsten Bögershausen 
On 2013-11-05 01.00, Ramsay Jones wrote:
 On 31/10/13 13:24, Torsten Bögershausen wrote:
 On 2013-10-30 22.07, Ramsay Jones wrote:
 [ ... ]
 Yep, this was the first thing I did as well! ;-) (*late* last night)

 I haven't had time today to look into fixing up the msvc build
 (or a complete re-write), so I look forward to seeing your solution.
 (do you have msvc available? - or do you want me to look at fixing
 it? maybe in a day or two?)

 Ramsay,
 I don't have msvc, so feel free to go ahead, as much as you can.

 I'll send a patch for the test code I have made, and put bswap.h on hold for 
 a week
 (to be able to continue with t5601/connect.c)
 
 Unfortunately, I haven't had much time to look into this.
 
 I do have a patch (given below) that works on Linux, cygwin,
 MinGW and msvc. However, the msvc build is still broken (as a
 result of _other_ commits in this 'jk/pack-bitmap' branch; as
 well as the use of a VLA in another commit).
 
 So, I still have work to do! :(
 
 Anyway, I thought I would send what I have, so you can take a look.
 Note, that I don't have an big-endian machine to test this on, so
 YMMV. Indeed, the *only* testing I have done is to run the test added
 by this branch (t5310-pack-bitmaps.sh), which works on Linux, cygwin
 and MinGW.
 
 [Note: I have never particularly liked htons, htonl et.al., so adding
 these htonll/ntohll functions doesn't thrill me! :-D For example see
 this post[1], which echo's my sentiments exactly.]
 
 HTH
 
 ATB,
 Ramsay Jones
 
 [1] http://commandcenter.blogspot.co.uk/2012/04/byte-order-fallacy.html
 
 -- 8 --
 Subject: [PATCH] compat/bswap.h: Fix build on cygwin, MinGW and msvc
 
 ---
  compat/bswap.h | 97 
 --
  1 file changed, 68 insertions(+), 29 deletions(-)
 
 diff --git a/compat/bswap.h b/compat/bswap.h
 index ea1a9ed..c18a78e 100644
 --- a/compat/bswap.h
 +++ b/compat/bswap.h
 @@ -17,7 +17,20 @@ static inline uint32_t default_swab32(uint32_t val)
   ((val  0x00ff)  24));
  }
  
 +static inline uint64_t default_bswap64(uint64_t val)
 +{
 + return (((val  (uint64_t)0x00ffULL)  56) |
 + ((val  (uint64_t)0xff00ULL)  40) |
 + ((val  (uint64_t)0x00ffULL)  24) |
 + ((val  (uint64_t)0xff00ULL)   8) |
 + ((val  (uint64_t)0x00ffULL)   8) |
 + ((val  (uint64_t)0xff00ULL)  24) |
 + ((val  (uint64_t)0x00ffULL)  40) |
 + ((val  (uint64_t)0xff00ULL)  56));
 +}
 +
  #undef bswap32
 +#undef bswap64
  
  #if defined(__GNUC__)  (defined(__i386__) || defined(__x86_64__))
  
 @@ -32,54 +45,80 @@ static inline uint32_t git_bswap32(uint32_t x)
   return result;
  }
  
 +#define bswap64 git_bswap64
 +#if defined(__x86_64__)
 +static inline uint64_t git_bswap64(uint64_t x)
 +{
 + uint64_t result;
 + if (__builtin_constant_p(x))
 + result = default_bswap64(x);
 + else
 + __asm__(bswap %q0 : =r (result) : 0 (x));
 + return result;
 +}
 +#else
 +static inline uint64_t git_bswap64(uint64_t x)
 +{
 + union { uint64_t i64; uint32_t i32[2]; } tmp, result;
 + if (__builtin_constant_p(x))
 + result.i64 = default_bswap64(x);
 + else {
 + tmp.i64 = x;
 + result.i32[0] = git_bswap32(tmp.i32[1]);
 + result.i32[1] = git_bswap32(tmp.i32[0]);
 + }
 + return result.i64;
 +}
 +#endif
 +
  #elif defined(_MSC_VER)  (defined(_M_IX86) || defined(_M_X64))
  
  #include stdlib.h
  
  #define bswap32(x) _byteswap_ulong(x)
 +#define bswap64(x) _byteswap_uint64(x)
  
  #endif
  
 -#ifdef bswap32
 +#if defined(bswap32)
  
  #undef ntohl
  #undef htonl
  #define ntohl(x) bswap32(x)
  #define htonl(x) bswap32(x)
  
 -#ifndef __BYTE_ORDER
 -#if defined(BYTE_ORDER)  defined(LITTLE_ENDIAN)  defined(BIG_ENDIAN)
 -#define __BYTE_ORDER BYTE_ORDER
 -#define __LITTLE_ENDIAN LITTLE_ENDIAN
 -#define __BIG_ENDIAN BIG_ENDIAN
 -#else
 -#error Cannot determine endianness
 -#endif
 +#endif
 +
 +#if defined(bswap64)
 +
 +#undef ntohll
 +#undef htonll
 +#define ntohll(x) bswap64(x)
 +#define htonll(x) bswap64(x)
 +
 +#else
 +
 +#undef ntohll
 +#undef htonll
 +
 +#if !defined(__BYTE_ORDER)
 +# if defined(BYTE_ORDER)  defined(LITTLE_ENDIAN)  defined(BIG_ENDIAN)
 +#  define __BYTE_ORDER BYTE_ORDER
 +#  define __LITTLE_ENDIAN LITTLE_ENDIAN
 +#  define __BIG_ENDIAN BIG_ENDIAN
 +# endif
 +#endif
 +
 +#if !defined(__BYTE_ORDER)
 +# error Cannot determine endianness
  #endif
  
  #if __BYTE_ORDER == __BIG_ENDIAN
  # define ntohll(n) (n)
  # define htonll(n) (n)
 -#elif __BYTE_ORDER == __LITTLE_ENDIAN
 -#if defined(__GNUC__)  defined(__GLIBC__)
 -#include byteswap.h
 -#else /* GNUC  GLIBC */
 -static inline uint64_t bswap_64(uint64_t val)
 -{
 - return ((val  (uint64_t

Re: htonll, ntohll

2013-11-04 Thread Ramsay Jones 
On 31/10/13 13:24, Torsten Bögershausen wrote:
 On 2013-10-30 22.07, Ramsay Jones wrote:
[ ... ]
 Yep, this was the first thing I did as well! ;-) (*late* last night)

 I haven't had time today to look into fixing up the msvc build
 (or a complete re-write), so I look forward to seeing your solution.
 (do you have msvc available? - or do you want me to look at fixing
 it? maybe in a day or two?)

 Ramsay,
 I don't have msvc, so feel free to go ahead, as much as you can.
 
 I'll send a patch for the test code I have made, and put bswap.h on hold for 
 a week
 (to be able to continue with t5601/connect.c)

Unfortunately, I haven't had much time to look into this.

I do have a patch (given below) that works on Linux, cygwin,
MinGW and msvc. However, the msvc build is still broken (as a
result of _other_ commits in this 'jk/pack-bitmap' branch; as
well as the use of a VLA in another commit).

So, I still have work to do! :(

Anyway, I thought I would send what I have, so you can take a look.
Note, that I don't have an big-endian machine to test this on, so
YMMV. Indeed, the *only* testing I have done is to run the test added
by this branch (t5310-pack-bitmaps.sh), which works on Linux, cygwin
and MinGW.

[Note: I have never particularly liked htons, htonl et.al., so adding
these htonll/ntohll functions doesn't thrill me! :-D For example see
this post[1], which echo's my sentiments exactly.]

HTH

ATB,
Ramsay Jones

[1] http://commandcenter.blogspot.co.uk/2012/04/byte-order-fallacy.html

-- 8 --
Subject: [PATCH] compat/bswap.h: Fix build on cygwin, MinGW and msvc

---
 compat/bswap.h | 97 --
 1 file changed, 68 insertions(+), 29 deletions(-)

diff --git a/compat/bswap.h b/compat/bswap.h
index ea1a9ed..c18a78e 100644
--- a/compat/bswap.h
+++ b/compat/bswap.h
@@ -17,7 +17,20 @@ static inline uint32_t default_swab32(uint32_t val)
((val  0x00ff)  24));
 }
 
+static inline uint64_t default_bswap64(uint64_t val)
+{
+   return (((val  (uint64_t)0x00ffULL)  56) |
+   ((val  (uint64_t)0xff00ULL)  40) |
+   ((val  (uint64_t)0x00ffULL)  24) |
+   ((val  (uint64_t)0xff00ULL)   8) |
+   ((val  (uint64_t)0x00ffULL)   8) |
+   ((val  (uint64_t)0xff00ULL)  24) |
+   ((val  (uint64_t)0x00ffULL)  40) |
+   ((val  (uint64_t)0xff00ULL)  56));
+}
+
 #undef bswap32
+#undef bswap64
 
 #if defined(__GNUC__)  (defined(__i386__) || defined(__x86_64__))
 
@@ -32,54 +45,80 @@ static inline uint32_t git_bswap32(uint32_t x)
return result;
 }
 
+#define bswap64 git_bswap64
+#if defined(__x86_64__)
+static inline uint64_t git_bswap64(uint64_t x)
+{
+   uint64_t result;
+   if (__builtin_constant_p(x))
+   result = default_bswap64(x);
+   else
+   __asm__(bswap %q0 : =r (result) : 0 (x));
+   return result;
+}
+#else
+static inline uint64_t git_bswap64(uint64_t x)
+{
+   union { uint64_t i64; uint32_t i32[2]; } tmp, result;
+   if (__builtin_constant_p(x))
+   result.i64 = default_bswap64(x);
+   else {
+   tmp.i64 = x;
+   result.i32[0] = git_bswap32(tmp.i32[1]);
+   result.i32[1] = git_bswap32(tmp.i32[0]);
+   }
+   return result.i64;
+}
+#endif
+
 #elif defined(_MSC_VER)  (defined(_M_IX86) || defined(_M_X64))
 
 #include stdlib.h
 
 #define bswap32(x) _byteswap_ulong(x)
+#define bswap64(x) _byteswap_uint64(x)
 
 #endif
 
-#ifdef bswap32
+#if defined(bswap32)
 
 #undef ntohl
 #undef htonl
 #define ntohl(x) bswap32(x)
 #define htonl(x) bswap32(x)
 
-#ifndef __BYTE_ORDER
-#  if defined(BYTE_ORDER)  defined(LITTLE_ENDIAN)  defined(BIG_ENDIAN)
-#  define __BYTE_ORDER BYTE_ORDER
-#  define __LITTLE_ENDIAN LITTLE_ENDIAN
-#  define __BIG_ENDIAN BIG_ENDIAN
-#  else
-#  error Cannot determine endianness
-#  endif
+#endif
+
+#if defined(bswap64)
+
+#undef ntohll
+#undef htonll
+#define ntohll(x) bswap64(x)
+#define htonll(x) bswap64(x)
+
+#else
+
+#undef ntohll
+#undef htonll
+
+#if !defined(__BYTE_ORDER)
+# if defined(BYTE_ORDER)  defined(LITTLE_ENDIAN)  defined(BIG_ENDIAN)
+#  define __BYTE_ORDER BYTE_ORDER
+#  define __LITTLE_ENDIAN LITTLE_ENDIAN
+#  define __BIG_ENDIAN BIG_ENDIAN
+# endif
+#endif
+
+#if !defined(__BYTE_ORDER)
+# error Cannot determine endianness
 #endif
 
 #if __BYTE_ORDER == __BIG_ENDIAN
 # define ntohll(n) (n)
 # define htonll(n) (n)
-#elif __BYTE_ORDER == __LITTLE_ENDIAN
-#  if defined(__GNUC__)  defined(__GLIBC__)
-#  include byteswap.h
-#  else /* GNUC  GLIBC */
-static inline uint64_t bswap_64(uint64_t val)
-{
-   return ((val  (uint64_t)0x00ffULL)  56)
-   | ((val  (uint64_t)0xff00ULL)  40)
-   | ((val  (uint64_t

Re: htonll, ntohll

2013-10-31 Thread Torsten Bögershausen 
On 2013-10-30 22.07, Ramsay Jones wrote:
 On 30/10/13 20:30, Torsten Bögershausen wrote:
 On 2013-10-30 20.06, Ramsay Jones wrote:
 On 30/10/13 17:14, Torsten Bögershausen wrote:
 On 2013-10-30 18.01, Vicent Martí wrote:
 On Wed, Oct 30, 2013 at 5:51 PM, Torsten Bögershausen tbo...@web.de 
 wrote:
 There is a name clash under cygwin 1.7 (1.5 is OK)
 The following first aid hot fix works for me:
 /Torsten

 If Cygwin declares its own bswap_64, wouldn't it be better to use it
 instead of overwriting it with our own?
 Yes,
 this will be part of a longer patch.
 I found that some systems have something like this:

 #define htobe64(x) bswap_64(x)
 And bswap_64 is a function, so we can not detect it by asking
 #ifdef bswap_64
 ..
 #endif


 But we can use
 #ifdef htobe64
 ...
 #endif
 and this will be part of a bigger patch.

 And, in general, we should avoid to introduce functions which may have a
 name clash.
 Using the git_ prefix for function names is a good practice.
 So in order to unbrake the compilation error under cygwin 17,
 the hotfix can be used.

 heh, my patch (given below) took a different approach, but 

 ATB,
 Ramsay Jones

 -- 8 --
 Subject: [PATCH] compat/bswap.h: Fix redefinition of bswap_64 error on 
 cygwin
 MIME-Version: 1.0
 Content-Type: text/plain; charset=UTF-8
 Content-Transfer-Encoding: 8bit

 Since commit 452e0f20 (compat: add endianness helpers, 24-10-2013)
 the cygwin build has failed like so:

 GIT_VERSION = 1.8.4.1.804.g1f3748b
 * new build flags
 CC credential-store.o
 In file included from git-compat-util.h:305:0,
  from cache.h:4,
  from credential-store.c:1:
 compat/bswap.h:67:24: error: redefinition of 'bswap_64'
 In file included from /usr/include/endian.h:32:0,
  from /usr/include/cygwin/types.h:21,
  from /usr/include/sys/types.h:473,
  from /usr/include/sys/unistd.h:9,
  from /usr/include/unistd.h:4,
  from git-compat-util.h:98,
  from cache.h:4,
  from credential-store.c:1:
 /usr/include/byteswap.h:31:1: note: previous definition of \
 ‘bswap_64’ was here
 Makefile:1985: recipe for target 'credential-store.o' failed
 make: *** [credential-store.o] Error 1

 Note that cygwin has a defintion of 'bswap_64' in the byteswap.h
 header file (which had already been included by git-compat-util.h).
 In order to suppress the error, ensure that the byteswap.h header
 is included, just like the __GNUC__/__GLIBC__ case, rather than
 attempting to define a fallback implementation.

 Signed-off-by: Ramsay Jones ram...@ramsay1.demon.co.uk
 ---
  compat/bswap.h | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

 diff --git a/compat/bswap.h b/compat/bswap.h
 index ea1a9ed..b864abd 100644
 --- a/compat/bswap.h
 +++ b/compat/bswap.h
 @@ -61,7 +61,7 @@ static inline uint32_t git_bswap32(uint32_t x)
  # define ntohll(n) (n)
  # define htonll(n) (n)
  #elif __BYTE_ORDER == __LITTLE_ENDIAN
 -#  if defined(__GNUC__)  defined(__GLIBC__)
 +#  if defined(__GNUC__)  (defined(__GLIBC__) || defined(__CYGWIN__))
  #  include byteswap.h
  #  else /* GNUC  GLIBC */
  static inline uint64_t bswap_64(uint64_t val)


 Nice, much better.

 And here comes a patch for a big endian machine.
 I tryied to copy-paste a patch in my mail program,
 not sure if this applies.

 -- 8 --
 Subject: [PATCH] compat/bswap.h: htonll and ntohll for big endian

 Since commit 452e0f20 (compat: add endianness helpers, 24-10-2013)
 the build on a Linux/ppc gave a warning like this:
 CC ewah/ewah_io.o
 ewah/ewah_io.c: In function ‘ewah_serialize_to’:
 ewah/ewah_io.c:81: warning: implicit declaration of function ‘htonll’
 ewah/ewah_io.c: In function ‘ewah_read_mmap’:
 ewah/ewah_io.c:132: warning: implicit declaration of function ‘ntohll’

 Fix it by placing the #endif for #ifdef bswap32 at the right place.

 Signed-off-by: Torsten Bögershausen tbo...@web.de
 ---
  compat/bswap.h | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

 diff --git a/compat/bswap.h b/compat/bswap.h
 index ea1a9ed..b4ddab0
 --- a/compat/bswap.h
 +++ b/compat/bswap.h
 @@ -46,6 +46,7 @@ static inline uint32_t git_bswap32(uint32_t x)
  #undef htonl
  #define ntohl(x) bswap32(x)
  #define htonl(x) bswap32(x)
 +#endif
  
  #ifndef __BYTE_ORDER
  #  if defined(BYTE_ORDER)  defined(LITTLE_ENDIAN)  
 defined(BIG_ENDIAN)
 @@ -82,4 +83,3 @@ static inline uint64_t bswap_64(uint64_t val)
  #  error Can't define htonll or ntohll!
  #endif
  
 -#endif

 .

 
 Yep, this was the first thing I did as well! ;-) (*late* last night)
 
 I haven't had time today to look into fixing up the msvc build
 (or a complete re-write), so I look forward to seeing your solution.
 (do you have msvc available? - or do you want me to look at fixing
 it? maybe in a day or two?)
 
 ATB,
 Ramsay Jones
Ramsay,
I don't have msvc, so feel

[PATCH] Test code for htonll, ntohll

2013-10-31 Thread Torsten Bögershausen 

test-endianess.c adds test code for htonl(), ntohll()
and the recently introduced ntohll() and htonll()

The test is called in t0070

Signed-off-by: Torsten Bögershausen tbo...@web.de
---
 .gitignore |1 +
 Makefile   |3 +++
 t/t0070-fundamental.sh |3 +++
 test-endianess.c   |   58 
 4 files changed, 65 insertions(+)
 create mode 100644 test-endianess.c

diff --git a/.gitignore b/.gitignore
index 66199ed..750e7d8 100644
--- a/.gitignore
+++ b/.gitignore
@@ -183,6 +183,7 @@
 /test-date
 /test-delta
 /test-dump-cache-tree
+/test-endianess
 /test-scrap-cache-tree
 /test-genrandom
 /test-index-version
diff --git a/Makefile b/Makefile
index 07b0626..50957c7 100644
--- a/Makefile
+++ b/Makefile
@@ -555,6 +555,7 @@ TEST_PROGRAMS_NEED_X += test-ctype
 TEST_PROGRAMS_NEED_X += test-date
 TEST_PROGRAMS_NEED_X += test-delta
 TEST_PROGRAMS_NEED_X += test-dump-cache-tree
+TEST_PROGRAMS_NEED_X += test-endianess
 TEST_PROGRAMS_NEED_X += test-genrandom
 TEST_PROGRAMS_NEED_X += test-hashmap
 TEST_PROGRAMS_NEED_X += test-index-version
@@ -2275,6 +2276,8 @@ test-date$X: date.o ctype.o
 
 test-delta$X: diff-delta.o patch-delta.o
 
+test-endianess$X: test-endianess.c
+
 test-line-buffer$X: vcs-svn/lib.a
 
 test-parse-options$X: parse-options.o parse-options-cb.o
diff --git a/t/t0070-fundamental.sh b/t/t0070-fundamental.sh
index 5ed69a6..dc687da 100755
--- a/t/t0070-fundamental.sh
+++ b/t/t0070-fundamental.sh
@@ -33,5 +33,8 @@ test_expect_success 'check for a bug in the regex routines' '
# if this test fails, re-build git with NO_REGEX=1
test-regex
 '
+test_expect_success 'test endianess, htonll(), ntohll()' '
+   test-endianess
+'
 
 test_done
diff --git a/test-endianess.c b/test-endianess.c
new file mode 100644
index 000..5b49175
--- /dev/null
+++ b/test-endianess.c
@@ -0,0 +1,58 @@
+#include cache.h
+
+int main(int argc, char **argv)
+{
+   union {
+   uint8_t  bytes[8];
+   uint32_t word32;
+   uint64_t word64;
+   } wordll;
+   volatile uint64_t word64;
+   volatile uint32_t word32;
+
+   wordll.bytes[0] = 0x80;
+   wordll.bytes[1] = 0x81;
+   wordll.bytes[2] = 0x82;
+   wordll.bytes[3] = 0x83;
+   wordll.bytes[4] = 0x00;
+   wordll.bytes[5] = 0x01;
+   wordll.bytes[6] = 0x02;
+   wordll.bytes[7] = 0x03;
+
+   word32 = htonl(wordll.word32);
+   if (word32 != 0x80818283)
+   die(htonl word32 != 0x80818283);
+
+   word64 = htonll(wordll.word64);
+   if (word64 != 0x8081828300010203ULL)
+   die(htonll word64 != 0x8081828300010203);
+
+   word32 = ntohl(wordll.word32);
+   if (word32 != 0x80818283)
+   die(ntohl word32 != 0x80818283);
+
+   word64 = ntohll(wordll.word64);
+   if (word64 != 0x8081828300010203ULL)
+   die(ntohll word64 != 0x8081828300010203);
+
+   wordll.bytes[0] = 0x04;
+   wordll.bytes[4] = 0x84;
+
+   word32 = htonl(wordll.word32);
+   if (word32 != 0x04818283)
+   die(htonl word32 != 0x04818283);
+
+   word64 = htonll(wordll.word64);
+   if (word64 != 0x0481828384010203ULL)
+   die(htonll word64 != 0x0481828384010203);
+
+   word32 = ntohl(wordll.word32);
+   if (word32 != 0x04818283)
+   die(ntohl word32 != 0x04818283);
+
+   word64 = ntohll(wordll.word64);
+   if (word64 != 0x0481828384010203ULL)
+   die(ntohll word64 != 0x0481828384010203);
+
+   return 0;
+}
-- 
1.7.10.4

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