varint: make it available outside the context of pack
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Junio C Hamano committed
Apr 3, 2012 at 15:53 UTC
d2c1898571a6a2324593e92163e8754880e0c1fb
3 files changed
+40
Makefile
+2
@@ -627,6 +627,7 @@ LIB_H += tree-walk.h
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LIB_H += unpack-trees.h
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LIB_H += userdiff.h
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LIB_H += utf8.h
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+LIB_H += varint.h
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LIB_H += xdiff-interface.h
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LIB_H += xdiff/xdiff.h
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@@ -752,6 +753,7 @@ LIB_OBJS += url.o
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LIB_OBJS += usage.o
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LIB_OBJS += userdiff.o
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LIB_OBJS += utf8.o
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+LIB_OBJS += varint.o
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LIB_OBJS += walker.o
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LIB_OBJS += wrapper.o
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LIB_OBJS += write_or_die.o
varint.c
new
+29
@@ -0,0 +1,29 @@
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+#include "varint.h"
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+
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+uintmax_t decode_varint(const unsigned char **bufp)
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+{
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+ const unsigned char *buf = *bufp;
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+ unsigned char c = *buf++;
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+ uintmax_t val = c & 127;
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+ while (c & 128) {
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+ val += 1;
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+ if (!val || MSB(val, 7))
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+ return 0; /* overflow */
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+ c = *buf++;
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+ val = (val << 7) + (c & 127);
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+ }
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+ *bufp = buf;
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+ return val;
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+}
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+
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+int encode_varint(uintmax_t value, unsigned char *buf)
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+{
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+ unsigned char varint[16];
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+ unsigned pos = sizeof(varint) - 1;
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+ varint[pos] = value & 127;
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+ while (value >>= 7)
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+ varint[--pos] = 128 | (--value & 127);
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+ if (buf)
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+ memcpy(buf, varint + pos, sizeof(varint) - pos);
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+ return sizeof(varint) - pos;
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+}
varint.h
new
+9
@@ -0,0 +1,9 @@
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+#ifndef VARINT_H
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+#define VARINT_H
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+
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+#include "git-compat-util.h"
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+
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+extern int encode_varint(uintmax_t, unsigned char *);
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+extern uintmax_t decode_varint(const unsigned char **);
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+
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+#endif /* VARINT_H */