Move from cmp --> eq, and provide a good implementation for interning

3 files changed, 14 insertions, 7 deletions

diff --git a/src/core/lib/transport/metadata.c b/src/core/lib/transport/metadata.c
index 2082d1bac2..f9f5ac9dd2 100644
--- a/src/core/lib/transport/metadata.c
+++ b/src/core/lib/transport/metadata.c
@@ -279,8 +279,7 @@ grpc_mdelem grpc_mdelem_create(
   idx = TABLE_IDX(hash, shard->capacity);
   /* search for an existing pair */
   for (md = shard->elems[idx]; md; md = md->bucket_next) {
-    if (grpc_slice_cmp(key, md->key) == 0 &&
-        grpc_slice_cmp(value, md->value) == 0) {
+    if (grpc_slice_eq(key, md->key) && grpc_slice_eq(value, md->value)) {
       REF_MD_LOCKED(shard, md);
       gpr_mu_unlock(&shard->mu);
       GPR_TIMER_END("grpc_mdelem_from_metadata_strings", 0);
@@ -496,7 +495,8 @@ void *grpc_mdelem_set_user_data(grpc_mdelem md, void (*destroy_func)(void *),
 
 bool grpc_mdelem_eq(grpc_mdelem a, grpc_mdelem b) {
   if (a.payload == b.payload) return true;
+  if (GRPC_MDELEM_IS_INTERNED(a) && GRPC_MDELEM_IS_INTERNED(b)) return false;
   if (GRPC_MDISNULL(a) || GRPC_MDISNULL(b)) return false;
-  return 0 == grpc_slice_cmp(GRPC_MDKEY(a), GRPC_MDKEY(b)) &&
-         0 == grpc_slice_cmp(GRPC_MDVALUE(a), GRPC_MDVALUE(b));
+  return grpc_slice_eq(GRPC_MDKEY(a), GRPC_MDKEY(b)) &&
+         grpc_slice_eq(GRPC_MDVALUE(a), GRPC_MDVALUE(b));
 }
diff --git a/src/core/lib/transport/metadata.h b/src/core/lib/transport/metadata.h
index 6d0afbe789..f4ba86c854 100644
--- a/src/core/lib/transport/metadata.h
+++ b/src/core/lib/transport/metadata.h
@@ -86,17 +86,21 @@ typedef struct grpc_mdelem_data {
   /* there is a private part to this in metadata.c */
 } grpc_mdelem_data;
 
+/* GRPC_MDELEM_STORAGE_* enum values that can be treated as interned always have
+   this bit set in their integer value */
+#define GRPC_MDELEM_STORAGE_INTERNED_BIT 1
+
 typedef enum {
   /* memory pointed to by grpc_mdelem::payload is owned by an external system */
   GRPC_MDELEM_STORAGE_EXTERNAL = 0,
   /* memory pointed to by grpc_mdelem::payload is interned by the metadata
      system */
-  GRPC_MDELEM_STORAGE_INTERNED = 1,
+  GRPC_MDELEM_STORAGE_INTERNED = GRPC_MDELEM_STORAGE_INTERNED_BIT,
   /* memory pointed to by grpc_mdelem::payload is allocated by the metadata
      system */
   GRPC_MDELEM_STORAGE_ALLOCATED = 2,
   /* memory is in the static metadata table */
-  GRPC_MDELEM_STORAGE_STATIC = 3,
+  GRPC_MDELEM_STORAGE_STATIC = 2 | GRPC_MDELEM_STORAGE_INTERNED_BIT,
 } grpc_mdelem_data_storage;
 
 struct grpc_mdelem {
@@ -111,6 +115,9 @@ struct grpc_mdelem {
   ((grpc_mdelem_data_storage)((md).payload & (uintptr_t)3))
 #define GRPC_MAKE_MDELEM(data, storage) \
   ((grpc_mdelem){((uintptr_t)(data)) | ((uintptr_t)storage)})
+#define GRPC_MDELEM_IS_INTERNED(md)          \
+  ((grpc_mdelem_data_storage)((md).payload & \
+                              (uintptr_t)GRPC_MDELEM_STORAGE_INTERNED_BIT))
 
 /* Unrefs the slices. */
 grpc_mdelem grpc_mdelem_from_slices(grpc_exec_ctx *exec_ctx, grpc_slice key,
diff --git a/src/core/lib/transport/static_metadata.c b/src/core/lib/transport/static_metadata.c
index 575f442a9b..374a5fd615 100644
--- a/src/core/lib/transport/static_metadata.c
+++ b/src/core/lib/transport/static_metadata.c
@@ -117,7 +117,7 @@ static uint8_t g_raw_bytes[] = {
 static void static_ref(void *unused) {}
 static void static_unref(grpc_exec_ctx *exec_ctx, void *unused) {}
 static const grpc_slice_refcount_vtable static_vtable = {
-    static_ref, static_unref, grpc_static_slice_hash};
+    static_ref, static_unref, grpc_static_slice_eq, grpc_static_slice_hash};
 static grpc_slice_refcount g_refcnt = {&static_vtable};
 
 bool grpc_is_static_metadata_string(grpc_slice slice) {