1 files changed, 201 insertions, 0 deletions
diff --git a/web/server/h2o/libh2o/lib/http2/cache_digests.c b/web/server/h2o/libh2o/lib/http2/cache_digests.c
new file mode 100644
index 00000000..fa28bd23
--- /dev/null
+++ b/web/server/h2o/libh2o/lib/http2/cache_digests.c
@@ -0,0 +1,201 @@
+/*
+ * Copyright (c) 2016 DeNA Co., Ltd., 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.
+ */
+#include <limits.h>
+#include <openssl/sha.h>
+#include <stdlib.h>
+#include "golombset.h"
+#include "h2o/string_.h"
+#include "h2o/cache_digests.h"
+
+struct st_h2o_cache_digests_frame_t {
+    H2O_VECTOR(uint64_t) keys;
+    unsigned capacity_bits;
+};
+
+static void dispose_frame_vector(h2o_cache_digests_frame_vector_t *v)
+{
+    size_t i;
+    for (i = 0; i != v->size; ++i)
+        free(v->entries[i].keys.entries);
+    free(v->entries);
+}
+
+static void dispose_digests(h2o_cache_digests_t *digests)
+{
+    dispose_frame_vector(&digests->fresh.url_only);
+    dispose_frame_vector(&digests->fresh.url_and_etag);
+}
+
+void h2o_cache_digests_destroy(h2o_cache_digests_t *digests)
+{
+    dispose_digests(digests);
+    free(digests);
+}
+
+static void load_digest(h2o_cache_digests_t **digests, const char *gcs_base64, size_t gcs_base64_len, int with_validators,
+                        int complete)
+{
+    h2o_cache_digests_frame_t frame = {{NULL}};
+    h2o_iovec_t gcs_bin;
+    struct st_golombset_decode_t ctx = {NULL};
+    uint64_t nbits, pbits;
+
+    /* decode base64 */
+    if ((gcs_bin = h2o_decode_base64url(NULL, gcs_base64, gcs_base64_len)).base == NULL)
+        goto Exit;
+
+    /* prepare GCS context */
+    ctx.src = (void *)(gcs_bin.base - 1);
+    ctx.src_max = (void *)(gcs_bin.base + gcs_bin.len);
+    ctx.src_shift = 0;
+
+    /* decode nbits and pbits */
+    if (golombset_decode_bits(&ctx, 5, &nbits) != 0 || golombset_decode_bits(&ctx, 5, &pbits) != 0)
+        goto Exit;
+    frame.capacity_bits = (unsigned)(nbits + pbits);
+
+    /* decode the values */
+    uint64_t value = UINT64_MAX, decoded;
+    while (golombset_decode_value(&ctx, (unsigned)pbits, &decoded) == 0) {
+        value += decoded + 1;
+        if (value >= (uint64_t)1 << frame.capacity_bits)
+            goto Exit;
+        h2o_vector_reserve(NULL, &frame.keys, frame.keys.size + 1);
+        frame.keys.entries[frame.keys.size++] = value;
+    }
+
+    /* store the result */
+    if (*digests == NULL) {
+        *digests = h2o_mem_alloc(sizeof(**digests));
+        **digests = (h2o_cache_digests_t){{{NULL}}};
+    }
+    h2o_cache_digests_frame_vector_t *target = with_validators ? &(*digests)->fresh.url_and_etag : &(*digests)->fresh.url_only;
+    h2o_vector_reserve(NULL, target, target->size + 1);
+    target->entries[target->size++] = frame;
+    frame = (h2o_cache_digests_frame_t){{NULL}};
+    (*digests)->fresh.complete = complete;
+
+Exit:
+    free(frame.keys.entries);
+    free(gcs_bin.base);
+}
+
+void h2o_cache_digests_load_header(h2o_cache_digests_t **digests, const char *value, size_t len)
+{
+    h2o_iovec_t iter = h2o_iovec_init(value, len);
+    const char *token;
+    size_t token_len;
+
+    do {
+        const char *gcs_base64;
+        size_t gcs_base64_len;
+        int reset = 0, validators = 0, complete = 0, skip = 0;
+        h2o_iovec_t token_value;
+
+        if ((gcs_base64 = h2o_next_token(&iter, ';', &gcs_base64_len, NULL)) == NULL)
+            return;
+        while ((token = h2o_next_token(&iter, ';', &token_len, &token_value)) != NULL &&
+               !h2o_memis(token, token_len, H2O_STRLIT(","))) {
+            if (h2o_lcstris(token, token_len, H2O_STRLIT("reset"))) {
+                reset = 1;
+            } else if (h2o_lcstris(token, token_len, H2O_STRLIT("validators"))) {
+                validators = 1;
+            } else if (h2o_lcstris(token, token_len, H2O_STRLIT("complete"))) {
+                complete = 1;
+            } else {
+                skip = 1;
+            }
+        }
+
+        if (reset && *digests != NULL) {
+            h2o_cache_digests_destroy(*digests);
+            *digests = NULL;
+        }
+
+        if (skip) {
+            /* not supported for the time being */
+        } else {
+            load_digest(digests, gcs_base64, gcs_base64_len, validators, complete);
+        }
+    } while (token != NULL);
+}
+
+static uint64_t calc_hash(const char *url, size_t url_len, const char *etag, size_t etag_len)
+{
+    SHA256_CTX ctx;
+    union {
+        unsigned char bytes[SHA256_DIGEST_LENGTH];
+        uint64_t u64;
+    } md;
+
+    SHA256_Init(&ctx);
+    SHA256_Update(&ctx, url, url_len);
+    SHA256_Update(&ctx, etag, etag_len);
+    SHA256_Final(md.bytes, &ctx);
+
+    if (*(uint16_t *)"\xde\xad" == 0xdead)
+        return md.u64;
+    else
+        return __builtin_bswap64(md.u64);
+}
+
+static int cmp_key(const void *_x, const void *_y)
+{
+    uint64_t x = *(uint64_t *)_x, y = *(uint64_t *)_y;
+
+    if (x < y) {
+        return -1;
+    } else if (x > y) {
+        return 1;
+    } else {
+        return 0;
+    }
+}
+
+static int lookup(h2o_cache_digests_frame_vector_t *vector, const char *url, size_t url_len, const char *etag, size_t etag_len,
+                  int is_fresh, int is_complete)
+{
+    if (vector->size != 0) {
+        uint64_t hash = calc_hash(url, url_len, etag, etag_len);
+        size_t i = 0;
+        do {
+            h2o_cache_digests_frame_t *frame = vector->entries + i;
+            uint64_t key = hash >> (64 - frame->capacity_bits);
+            if (frame->keys.entries != NULL &&
+                bsearch(&key, frame->keys.entries, frame->keys.size, sizeof(frame->keys.entries[0]), cmp_key) != NULL)
+                return is_fresh ? H2O_CACHE_DIGESTS_STATE_FRESH : H2O_CACHE_DIGESTS_STATE_STALE;
+        } while (++i != vector->size);
+    }
+
+    return is_complete ? H2O_CACHE_DIGESTS_STATE_NOT_CACHED : H2O_CACHE_DIGESTS_STATE_UNKNOWN;
+}
+
+h2o_cache_digests_state_t h2o_cache_digests_lookup_by_url(h2o_cache_digests_t *digests, const char *url, size_t url_len)
+{
+    return lookup(&digests->fresh.url_only, url, url_len, "", 0, 1, digests->fresh.complete);
+}
+
+h2o_cache_digests_state_t h2o_cache_digests_lookup_by_url_and_etag(h2o_cache_digests_t *digests, const char *url, size_t url_len,
+                                                                   const char *etag, size_t etag_len)
+{
+    return lookup(&digests->fresh.url_and_etag, url, url_len, etag, etag_len, 1, digests->fresh.complete);
+}