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authorVincent Ambo <Vincent Ambo>2020-01-11T23·36+0000
committerVincent Ambo <Vincent Ambo>2020-01-11T23·36+0000
commit1b593e1ea4d2af0f6444d9a7788d5d99abd6fde5 (patch)
treee3accb9beed5c4c1b5a05c99db71ab2841f0ed04 /varint.c
Squashed 'third_party/git/' content from commit cb71568594
git-subtree-dir: third_party/git
git-subtree-split: cb715685942260375e1eb8153b0768a376e4ece7
Diffstat (limited to 'varint.c')
-rw-r--r--varint.c30
1 files changed, 30 insertions, 0 deletions
diff --git a/varint.c b/varint.c
new file mode 100644
index 000000000000..409c4977a1e3
--- /dev/null
+++ b/varint.c
@@ -0,0 +1,30 @@
+#include "git-compat-util.h"
+#include "varint.h"
+
+uintmax_t decode_varint(const unsigned char **bufp)
+{
+	const unsigned char *buf = *bufp;
+	unsigned char c = *buf++;
+	uintmax_t val = c & 127;
+	while (c & 128) {
+		val += 1;
+		if (!val || MSB(val, 7))
+			return 0; /* overflow */
+		c = *buf++;
+		val = (val << 7) + (c & 127);
+	}
+	*bufp = buf;
+	return val;
+}
+
+int encode_varint(uintmax_t value, unsigned char *buf)
+{
+	unsigned char varint[16];
+	unsigned pos = sizeof(varint) - 1;
+	varint[pos] = value & 127;
+	while (value >>= 7)
+		varint[--pos] = 128 | (--value & 127);
+	if (buf)
+		memcpy(buf, varint + pos, sizeof(varint) - pos);
+	return sizeof(varint) - pos;
+}