1 files changed, 162 insertions, 0 deletions
diff --git a/web/server/h2o/libh2o/deps/golombset/golombset.h b/web/server/h2o/libh2o/deps/golombset/golombset.h
new file mode 100644
index 00000000..207f0d61
--- /dev/null
+++ b/web/server/h2o/libh2o/deps/golombset/golombset.h
@@ -0,0 +1,162 @@
+/*
+ * Copyright (c) 2015 Kazuho Oku
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+#ifndef GOLOMBSET_H
+#define GOLOMBSET_H
+
+#include <inttypes.h>
+
+struct st_golombset_encode_t {
+    unsigned char *dst;
+    unsigned char *dst_max;
+    unsigned dst_shift;
+};
+
+struct st_golombset_decode_t {
+    const unsigned char *src;
+    const unsigned char *src_max;
+    unsigned src_shift;
+};
+
+static int golombset_encode_bit(struct st_golombset_encode_t *ctx, int bit)
+{
+    if (ctx->dst_shift == 0) {
+        if (++ctx->dst == ctx->dst_max)
+            return -1;
+        *ctx->dst = 0;
+        ctx->dst_shift = 8;
+    }
+    --ctx->dst_shift;
+    if (bit)
+        *ctx->dst |= 1 << ctx->dst_shift;
+    return 0;
+}
+
+static int golombset_encode_bits(struct st_golombset_encode_t *ctx, unsigned bits, uint64_t value)
+{
+    if (bits != 0) {
+        do {
+            --bits;
+            if (golombset_encode_bit(ctx, (value >> bits) & 1) != 0)
+                return -1;
+        } while (bits != 0);
+    }
+    return 0;
+}
+
+static int golombset_decode_bit(struct st_golombset_decode_t *ctx)
+{
+    if (ctx->src_shift == 0) {
+        if (++ctx->src == ctx->src_max)
+            return -1;
+        ctx->src_shift = 8;
+    }
+    return (*ctx->src >> --ctx->src_shift) & 1;
+}
+
+static int golombset_decode_bits(struct st_golombset_decode_t *ctx, unsigned bits, uint64_t *value)
+{
+    int bit;
+
+    *value = 0;
+    for (; bits != 0; --bits) {
+        if ((bit = golombset_decode_bit(ctx)) == -1)
+            return -1;
+        *value = (*value * 2) + bit;
+    }
+
+    return 0;
+}
+
+static int golombset_encode_value(struct st_golombset_encode_t *ctx, unsigned fixed_bits, uint64_t value)
+{
+    /* emit quontient */
+    uint64_t unary_bits = value >> fixed_bits;
+    for (; unary_bits != 0; --unary_bits)
+        if (golombset_encode_bit(ctx, 0) != 0)
+            return -1;
+    if (golombset_encode_bit(ctx, 1) != 0)
+        return -1;
+    /* emit remainder */
+    return golombset_encode_bits(ctx, fixed_bits, value);
+}
+
+static int golombset_decode_value(struct st_golombset_decode_t *ctx, unsigned fixed_bits, uint64_t *value)
+{
+    uint64_t q;
+    int bit;
+
+    /* decode quontient */
+    for (q = 0; ; ++q) {
+        if ((bit = golombset_decode_bit(ctx)) == -1)
+            return -1;
+        if (bit)
+            break;
+    }
+    /* decode remainder */
+    if (golombset_decode_bits(ctx, fixed_bits, value) == -1)
+        return -1;
+    /* merge q and r */
+    *value += q << fixed_bits;
+
+    return 0;
+}
+
+static int golombset_encode(unsigned fixed_bits, uint64_t *keys, size_t num_keys, void *buf, size_t *bufsize)
+{
+    struct st_golombset_encode_t ctx = {(unsigned char *)buf - 1, (unsigned char *)buf + *bufsize};
+    size_t i;
+    uint64_t next_min = 0;
+
+    for (i = 0; i != num_keys; ++i) {
+        if (golombset_encode_value(&ctx, fixed_bits, keys[i] - next_min) != 0)
+            return -1;
+        next_min = keys[i] + 1;
+    }
+
+    *bufsize = ctx.dst + 1 - (unsigned char *)buf;
+
+    return 0;
+}
+
+static int golombset_decode(unsigned fixed_bits, const void *buf, size_t bufsize, uint64_t *keys, size_t *num_keys)
+{
+    struct st_golombset_decode_t ctx = {buf, (unsigned char *)buf + bufsize, 8};
+    size_t index = 0;
+    uint64_t next_min = 0;
+
+    while (1) {
+        uint64_t value;
+        if (golombset_decode_value(&ctx, fixed_bits, &value) != 0)
+            break;
+        if (index == *num_keys) {
+            /* not enough space */
+            return -1;
+        }
+        value += next_min;
+        keys[index++] = value;
+        next_min = value + 1;
+    }
+    *num_keys = index;
+    return 0;
+}
+
+#endif