Initial checkin of gRPC to third_party/

third_party/grpc/src/core/transport/chttp2/hpack_table.c

Index: third_party/grpc/src/core/transport/chttp2/hpack_table.c
diff --git a/third_party/grpc/src/core/transport/chttp2/hpack_table.c b/third_party/grpc/src/core/transport/chttp2/hpack_table.c
new file mode 100644
index 0000000000000000000000000000000000000000..f1ce3b84fdccae84ac1495e8e22ef4d8a862cffc
--- /dev/null
+++ b/third_party/grpc/src/core/transport/chttp2/hpack_table.c
@@ -0,0 +1,361 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/transport/chttp2/hpack_table.h"
+
+#include <assert.h>
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+
+#include "src/core/support/murmur_hash.h"
+
+static struct {
+  const char *key;
+  const char *value;
+} static_table[] = {
+    /* 0: */
+    {NULL, NULL},
+    /* 1: */
+    {":authority", ""},
+    /* 2: */
+    {":method", "GET"},
+    /* 3: */
+    {":method", "POST"},
+    /* 4: */
+    {":path", "/"},
+    /* 5: */
+    {":path", "/index.html"},
+    /* 6: */
+    {":scheme", "http"},
+    /* 7: */
+    {":scheme", "https"},
+    /* 8: */
+    {":status", "200"},
+    /* 9: */
+    {":status", "204"},
+    /* 10: */
+    {":status", "206"},
+    /* 11: */
+    {":status", "304"},
+    /* 12: */
+    {":status", "400"},
+    /* 13: */
+    {":status", "404"},
+    /* 14: */
+    {":status", "500"},
+    /* 15: */
+    {"accept-charset", ""},
+    /* 16: */
+    {"accept-encoding", "gzip, deflate"},
+    /* 17: */
+    {"accept-language", ""},
+    /* 18: */
+    {"accept-ranges", ""},
+    /* 19: */
+    {"accept", ""},
+    /* 20: */
+    {"access-control-allow-origin", ""},
+    /* 21: */
+    {"age", ""},
+    /* 22: */
+    {"allow", ""},
+    /* 23: */
+    {"authorization", ""},
+    /* 24: */
+    {"cache-control", ""},
+    /* 25: */
+    {"content-disposition", ""},
+    /* 26: */
+    {"content-encoding", ""},
+    /* 27: */
+    {"content-language", ""},
+    /* 28: */
+    {"content-length", ""},
+    /* 29: */
+    {"content-location", ""},
+    /* 30: */
+    {"content-range", ""},
+    /* 31: */
+    {"content-type", ""},
+    /* 32: */
+    {"cookie", ""},
+    /* 33: */
+    {"date", ""},
+    /* 34: */
+    {"etag", ""},
+    /* 35: */
+    {"expect", ""},
+    /* 36: */
+    {"expires", ""},
+    /* 37: */
+    {"from", ""},
+    /* 38: */
+    {"host", ""},
+    /* 39: */
+    {"if-match", ""},
+    /* 40: */
+    {"if-modified-since", ""},
+    /* 41: */
+    {"if-none-match", ""},
+    /* 42: */
+    {"if-range", ""},
+    /* 43: */
+    {"if-unmodified-since", ""},
+    /* 44: */
+    {"last-modified", ""},
+    /* 45: */
+    {"link", ""},
+    /* 46: */
+    {"location", ""},
+    /* 47: */
+    {"max-forwards", ""},
+    /* 48: */
+    {"proxy-authenticate", ""},
+    /* 49: */
+    {"proxy-authorization", ""},
+    /* 50: */
+    {"range", ""},
+    /* 51: */
+    {"referer", ""},
+    /* 52: */
+    {"refresh", ""},
+    /* 53: */
+    {"retry-after", ""},
+    /* 54: */
+    {"server", ""},
+    /* 55: */
+    {"set-cookie", ""},
+    /* 56: */
+    {"strict-transport-security", ""},
+    /* 57: */
+    {"transfer-encoding", ""},
+    /* 58: */
+    {"user-agent", ""},
+    /* 59: */
+    {"vary", ""},
+    /* 60: */
+    {"via", ""},
+    /* 61: */
+    {"www-authenticate", ""},
+};
+
+static uint32_t entries_for_bytes(uint32_t bytes) {
+  return (bytes + GRPC_CHTTP2_HPACK_ENTRY_OVERHEAD - 1) /
+         GRPC_CHTTP2_HPACK_ENTRY_OVERHEAD;
+}
+
+void grpc_chttp2_hptbl_init(grpc_chttp2_hptbl *tbl) {
+  size_t i;
+
+  memset(tbl, 0, sizeof(*tbl));
+  tbl->current_table_bytes = tbl->max_bytes =
+      GRPC_CHTTP2_INITIAL_HPACK_TABLE_SIZE;
+  tbl->max_entries = tbl->cap_entries =
+      entries_for_bytes(tbl->current_table_bytes);
+  tbl->ents = gpr_malloc(sizeof(*tbl->ents) * tbl->cap_entries);
+  memset(tbl->ents, 0, sizeof(*tbl->ents) * tbl->cap_entries);
+  for (i = 1; i <= GRPC_CHTTP2_LAST_STATIC_ENTRY; i++) {
+    tbl->static_ents[i - 1] =
+        grpc_mdelem_from_strings(static_table[i].key, static_table[i].value);
+  }
+}
+
+void grpc_chttp2_hptbl_destroy(grpc_chttp2_hptbl *tbl) {
+  size_t i;
+  for (i = 0; i < GRPC_CHTTP2_LAST_STATIC_ENTRY; i++) {
+    GRPC_MDELEM_UNREF(tbl->static_ents[i]);
+  }
+  for (i = 0; i < tbl->num_ents; i++) {
+    GRPC_MDELEM_UNREF(tbl->ents[(tbl->first_ent + i) % tbl->cap_entries]);
+  }
+  gpr_free(tbl->ents);
+}
+
+grpc_mdelem *grpc_chttp2_hptbl_lookup(const grpc_chttp2_hptbl *tbl,
+                                      uint32_t tbl_index) {
+  /* Static table comes first, just return an entry from it */
+  if (tbl_index <= GRPC_CHTTP2_LAST_STATIC_ENTRY) {
+    return tbl->static_ents[tbl_index - 1];
+  }
+  /* Otherwise, find the value in the list of valid entries */
+  tbl_index -= (GRPC_CHTTP2_LAST_STATIC_ENTRY + 1);
+  if (tbl_index < tbl->num_ents) {
+    uint32_t offset =
+        (tbl->num_ents - 1u - tbl_index + tbl->first_ent) % tbl->cap_entries;
+    return tbl->ents[offset];
+  }
+  /* Invalid entry: return error */
+  return NULL;
+}
+
+/* Evict one element from the table */
+static void evict1(grpc_chttp2_hptbl *tbl) {
+  grpc_mdelem *first_ent = tbl->ents[tbl->first_ent];
+  size_t elem_bytes = GPR_SLICE_LENGTH(first_ent->key->slice) +
+                      GPR_SLICE_LENGTH(first_ent->value->slice) +
+                      GRPC_CHTTP2_HPACK_ENTRY_OVERHEAD;
+  GPR_ASSERT(elem_bytes <= tbl->mem_used);
+  tbl->mem_used -= (uint32_t)elem_bytes;
+  tbl->first_ent = ((tbl->first_ent + 1) % tbl->cap_entries);
+  tbl->num_ents--;
+  GRPC_MDELEM_UNREF(first_ent);
+}
+
+static void rebuild_ents(grpc_chttp2_hptbl *tbl, uint32_t new_cap) {
+  grpc_mdelem **ents = gpr_malloc(sizeof(*ents) * new_cap);
+  uint32_t i;
+
+  for (i = 0; i < tbl->num_ents; i++) {
+    ents[i] = tbl->ents[(tbl->first_ent + i) % tbl->cap_entries];
+  }
+  gpr_free(tbl->ents);
+  tbl->ents = ents;
+  tbl->cap_entries = new_cap;
+  tbl->first_ent = 0;
+}
+
+void grpc_chttp2_hptbl_set_max_bytes(grpc_chttp2_hptbl *tbl,
+                                     uint32_t max_bytes) {
+  if (tbl->max_bytes == max_bytes) {
+    return;
+  }
+  gpr_log(GPR_DEBUG, "Update hpack parser max size to %d", max_bytes);
+  while (tbl->mem_used > max_bytes) {
+    evict1(tbl);
+  }
+  tbl->max_bytes = max_bytes;
+}
+
+int grpc_chttp2_hptbl_set_current_table_size(grpc_chttp2_hptbl *tbl,
+                                             uint32_t bytes) {
+  if (tbl->current_table_bytes == bytes) {
+    return 1;
+  }
+  if (bytes > tbl->max_bytes) {
+    gpr_log(GPR_ERROR,
+            "Attempt to make hpack table %d bytes when max is %d bytes", bytes,
+            tbl->max_bytes);
+    return 0;
+  }
+  gpr_log(GPR_DEBUG, "Update hpack parser table size to %d", bytes);
+  while (tbl->mem_used > bytes) {
+    evict1(tbl);
+  }
+  tbl->current_table_bytes = bytes;
+  tbl->max_entries = entries_for_bytes(bytes);
+  if (tbl->max_entries > tbl->cap_entries) {
+    rebuild_ents(tbl, GPR_MAX(tbl->max_entries, 2 * tbl->cap_entries));
+  } else if (tbl->max_entries < tbl->cap_entries / 3) {
+    uint32_t new_cap = GPR_MAX(tbl->max_entries, 16u);
+    if (new_cap != tbl->cap_entries) {
+      rebuild_ents(tbl, new_cap);
+    }
+  }
+  return 1;
+}
+
+int grpc_chttp2_hptbl_add(grpc_chttp2_hptbl *tbl, grpc_mdelem *md) {
+  /* determine how many bytes of buffer this entry represents */
+  size_t elem_bytes = GPR_SLICE_LENGTH(md->key->slice) +
+                      GPR_SLICE_LENGTH(md->value->slice) +
+                      GRPC_CHTTP2_HPACK_ENTRY_OVERHEAD;
+
+  if (tbl->current_table_bytes > tbl->max_bytes) {
+    gpr_log(GPR_ERROR,
+            "HPACK max table size reduced to %d but not reflected by hpack "
+            "stream (still at %d)",
+            tbl->max_bytes, tbl->current_table_bytes);
+    return 0;
+  }
+
+  /* we can't add elements bigger than the max table size */
+  if (elem_bytes > tbl->current_table_bytes) {
+    /* HPACK draft 10 section 4.4 states:
+     * If the size of the new entry is less than or equal to the maximum
+     * size, that entry is added to the table.  It is not an error to
+     * attempt to add an entry that is larger than the maximum size; an
+     * attempt to add an entry larger than the entire table causes
+     * the table
+     * to be emptied of all existing entries, and results in an
+     * empty table.
+     */
+    while (tbl->num_ents) {
+      evict1(tbl);
+    }
+    return 1;
+  }
+
+  /* evict entries to ensure no overflow */
+  while (elem_bytes > (size_t)tbl->current_table_bytes - tbl->mem_used) {
+    evict1(tbl);
+  }
+
+  /* copy the finalized entry in */
+  tbl->ents[(tbl->first_ent + tbl->num_ents) % tbl->cap_entries] =
+      GRPC_MDELEM_REF(md);
+
+  /* update accounting values */
+  tbl->num_ents++;
+  tbl->mem_used += (uint32_t)elem_bytes;
+  return 1;
+}
+
+grpc_chttp2_hptbl_find_result grpc_chttp2_hptbl_find(
+    const grpc_chttp2_hptbl *tbl, grpc_mdelem *md) {
+  grpc_chttp2_hptbl_find_result r = {0, 0};
+  uint32_t i;
+
+  /* See if the string is in the static table */
+  for (i = 0; i < GRPC_CHTTP2_LAST_STATIC_ENTRY; i++) {
+    grpc_mdelem *ent = tbl->static_ents[i];
+    if (md->key != ent->key) continue;
+    r.index = i + 1u;
+    r.has_value = md->value == ent->value;
+    if (r.has_value) return r;
+  }
+
+  /* Scan the dynamic table */
+  for (i = 0; i < tbl->num_ents; i++) {
+    uint32_t idx =
+        (uint32_t)(tbl->num_ents - i + GRPC_CHTTP2_LAST_STATIC_ENTRY);
+    grpc_mdelem *ent = tbl->ents[(tbl->first_ent + i) % tbl->cap_entries];
+    if (md->key != ent->key) continue;
+    r.index = idx;
+    r.has_value = md->value == ent->value;
+    if (r.has_value) return r;
+  }
+
+  return r;
+}