Move slice functions to vtable, implement hash

include/grpc/impl/codegen/slice.h

@@ -39,6 +39,8 @@
 
 #include <grpc/impl/codegen/exec_ctx_fwd.h>
 
+typedef struct grpc_slice grpc_slice;
+
 /* Slice API
 
    A slice represents a contiguous reference counted array of bytes.
@@ -52,14 +54,19 @@
    reference ownership semantics (who should call unref?) and mutability
    constraints (is the callee allowed to modify the slice?) */
 
+typedef struct grpc_slice_refcount_vtable {
+  void (*ref)(void *);
+  void (*unref)(grpc_exec_ctx *exec_ctx, void *);
+  uint32_t (*hash)(void *, grpc_slice slice);
+} grpc_slice_refcount_vtable;
+
 /* Reference count container for grpc_slice. Contains function pointers to
    increment and decrement reference counts. Implementations should cleanup
    when the reference count drops to zero.
    Typically client code should not touch this, and use grpc_slice_malloc,
    grpc_slice_new, or grpc_slice_new_with_len instead. */
 typedef struct grpc_slice_refcount {
-  void (*ref)(void *);
-  void (*unref)(grpc_exec_ctx *exec_ctx, void *);
+  const grpc_slice_refcount_vtable *vtable;
 } grpc_slice_refcount;
 
 #define GRPC_SLICE_INLINED_SIZE (sizeof(size_t) + sizeof(uint8_t *) - 1)
@@ -73,7 +80,7 @@ typedef struct grpc_slice_refcount {
 
    If the slice does not have a refcount, it represents an inlined small piece
    of data that is copied by value. */
-typedef struct grpc_slice {
+struct grpc_slice {
   struct grpc_slice_refcount *refcount;
   union {
     struct {
@@ -85,7 +92,7 @@ typedef struct grpc_slice {
       uint8_t bytes[GRPC_SLICE_INLINED_SIZE];
     } inlined;
   } data;
-} grpc_slice;
+};
 
 #define GRPC_SLICE_BUFFER_INLINE_ELEMENTS 8
 

include/grpc/slice.h

@@ -121,6 +121,8 @@ GPRAPI grpc_slice grpc_slice_split_head(grpc_slice *s, size_t split);
 
 GPRAPI grpc_slice grpc_empty_slice(void);
 
+GPRAPI uint32_t grpc_slice_default_hash_impl(void *, grpc_slice s);
+
 /* Returns <0 if a < b, ==0 if a == b, >0 if a > b
    The order is arbitrary, and is not guaranteed to be stable across different
    versions of the API. */

src/core/ext/transport/chttp2/transport/hpack_encoder.c

@@ -64,7 +64,7 @@
 /* don't consider adding anything bigger than this to the hpack table */
 #define MAX_DECODER_SPACE_USAGE 512
 
-static grpc_slice_refcount terminal_slice_refcount = {NULL, NULL};
+static grpc_slice_refcount terminal_slice_refcount = {NULL};
 static const grpc_slice terminal_slice = {&terminal_slice_refcount,
                                           .data.refcounted = {0, 0}};
 

src/core/lib/iomgr/resource_quota.c

@@ -366,11 +366,13 @@ static void ru_slice_unref(grpc_exec_ctx *exec_ctx, void *p) {
   }
 }
 
+static const grpc_slice_refcount_vtable ru_slice_vtable = {
+    ru_slice_ref, ru_slice_unref, grpc_slice_default_hash_impl};
+
 static grpc_slice ru_slice_create(grpc_resource_user *resource_user,
                                   size_t size) {
   ru_slice_refcount *rc = gpr_malloc(sizeof(ru_slice_refcount) + size);
-  rc->base.ref = ru_slice_ref;
-  rc->base.unref = ru_slice_unref;
+  rc->base.vtable = &ru_slice_vtable;
   gpr_ref_init(&rc->refs, 1);
   rc->resource_user = resource_user;
   rc->size = size;

src/core/lib/slice/slice.c

@@ -50,14 +50,14 @@ grpc_slice grpc_empty_slice(void) {
 
 grpc_slice grpc_slice_ref_internal(grpc_slice slice) {
   if (slice.refcount) {
-    slice.refcount->ref(slice.refcount);
+    slice.refcount->vtable->ref(slice.refcount);
   }
   return slice;
 }
 
 void grpc_slice_unref_internal(grpc_exec_ctx *exec_ctx, grpc_slice slice) {
   if (slice.refcount) {
-    slice.refcount->unref(exec_ctx, slice.refcount);
+    slice.refcount->vtable->unref(exec_ctx, slice.refcount);
   }
 }
 
@@ -78,7 +78,9 @@ void grpc_slice_unref(grpc_slice slice) {
 static void noop_ref(void *unused) {}
 static void noop_unref(grpc_exec_ctx *exec_ctx, void *unused) {}
 
-static grpc_slice_refcount noop_refcount = {noop_ref, noop_unref};
+static const grpc_slice_refcount_vtable noop_refcount_vtable = {
+    noop_ref, noop_unref, grpc_slice_default_hash_impl};
+static grpc_slice_refcount noop_refcount = {&noop_refcount_vtable};
 
 grpc_slice grpc_slice_from_static_string(const char *s) {
   grpc_slice slice;
@@ -110,14 +112,16 @@ static void new_slice_unref(grpc_exec_ctx *exec_ctx, void *p) {
   }
 }
 
+static const grpc_slice_refcount_vtable new_slice_vtable = {
+    new_slice_ref, new_slice_unref, grpc_slice_default_hash_impl};
+
 grpc_slice grpc_slice_new_with_user_data(void *p, size_t len,
                                          void (*destroy)(void *),
                                          void *user_data) {
   grpc_slice slice;
   new_slice_refcount *rc = gpr_malloc(sizeof(new_slice_refcount));
   gpr_ref_init(&rc->refs, 1);
-  rc->rc.ref = new_slice_ref;
-  rc->rc.unref = new_slice_unref;
+  rc->rc.vtable = &new_slice_vtable;
   rc->user_destroy = destroy;
   rc->user_data = user_data;
 
@@ -155,14 +159,16 @@ static void new_with_len_unref(grpc_exec_ctx *exec_ctx, void *p) {
   }
 }
 
+static const grpc_slice_refcount_vtable new_with_len_vtable = {
+    new_with_len_ref, new_with_len_unref, grpc_slice_default_hash_impl};
+
 grpc_slice grpc_slice_new_with_len(void *p, size_t len,
                                    void (*destroy)(void *, size_t)) {
   grpc_slice slice;
   new_with_len_slice_refcount *rc =
       gpr_malloc(sizeof(new_with_len_slice_refcount));
   gpr_ref_init(&rc->refs, 1);
-  rc->rc.ref = new_with_len_ref;
-  rc->rc.unref = new_with_len_unref;
+  rc->rc.vtable = &new_with_len_vtable;
   rc->user_destroy = destroy;
   rc->user_data = p;
   rc->user_length = len;
@@ -200,6 +206,9 @@ static void malloc_unref(grpc_exec_ctx *exec_ctx, void *p) {
   }
 }
 
+static const grpc_slice_refcount_vtable malloc_vtable = {
+    malloc_ref, malloc_unref, grpc_slice_default_hash_impl};
+
 grpc_slice grpc_slice_malloc(size_t length) {
   grpc_slice slice;
 
@@ -219,8 +228,7 @@ grpc_slice grpc_slice_malloc(size_t length) {
        this reference. */
     gpr_ref_init(&rc->refs, 1);
 
-    rc->base.ref = malloc_ref;
-    rc->base.unref = malloc_unref;
+    rc->base.vtable = &malloc_vtable;
 
     /* Build up the slice to be returned. */
     /* The slices refcount points back to the allocated block. */
@@ -273,7 +281,7 @@ grpc_slice grpc_slice_sub(grpc_slice source, size_t begin, size_t end) {
   } else {
     subset = grpc_slice_sub_no_ref(source, begin, end);
     /* Bump the refcount */
-    subset.refcount->ref(subset.refcount);
+    subset.refcount->vtable->ref(subset.refcount);
   }
   return subset;
 }
@@ -302,7 +310,7 @@ grpc_slice grpc_slice_split_tail(grpc_slice *source, size_t split) {
       /* Build the result */
       tail.refcount = source->refcount;
       /* Bump the refcount */
-      tail.refcount->ref(tail.refcount);
+      tail.refcount->vtable->ref(tail.refcount);
       /* Point into the source array */
       tail.data.refcounted.bytes = source->data.refcounted.bytes + split;
       tail.data.refcounted.length = tail_length;
@@ -340,7 +348,7 @@ grpc_slice grpc_slice_split_head(grpc_slice *source, size_t split) {
     /* Build the result */
     head.refcount = source->refcount;
     /* Bump the refcount */
-    head.refcount->ref(head.refcount);
+    head.refcount->vtable->ref(head.refcount);
     /* Point into the source array */
     head.data.refcounted.bytes = source->data.refcounted.bytes;
     head.data.refcounted.length = split;

src/core/lib/slice/slice_hash_table.c

@@ -40,7 +40,7 @@
 #include "src/core/lib/slice/slice_internal.h"
 #include "src/core/lib/transport/metadata.h"
 
-static grpc_slice_refcount terminal_slice_refcount = {NULL, NULL};
+static grpc_slice_refcount terminal_slice_refcount = {NULL};
 static const grpc_slice terminal_slice = {&terminal_slice_refcount,
                                           .data.refcounted = {0, 0}};
 

src/core/lib/slice/slice_intern.c

@@ -100,6 +100,18 @@ static void interned_slice_unref(grpc_exec_ctx *exec_ctx, void *p) {
   }
 }
 
+static uint32_t interned_slice_hash(void *p, grpc_slice slice) {
+  interned_slice_refcount *s = p;
+  if (slice.data.refcounted.bytes == (uint8_t *)(s + 1) &&
+      slice.data.refcounted.length == s->length) {
+    return s->hash;
+  }
+  return grpc_slice_default_hash_impl(p, slice);
+}
+
+static const grpc_slice_refcount_vtable interned_slice_vtable = {
+    interned_slice_ref, interned_slice_unref, interned_slice_hash};
+
 static void grow_shard(slice_shard *shard) {
   size_t capacity = shard->capacity * 2;
   size_t i;
@@ -135,6 +147,16 @@ static grpc_slice materialize(interned_slice_refcount *s) {
   return slice;
 }
 
+uint32_t grpc_slice_default_hash_impl(void *unused_refcnt, grpc_slice s) {
+  return gpr_murmur_hash3(GRPC_SLICE_START_PTR(s), GRPC_SLICE_LENGTH(s),
+                          g_hash_seed);
+}
+
+uint32_t grpc_slice_hash(grpc_slice s) {
+  return s.refcount == NULL ? grpc_slice_default_hash_impl(NULL, s)
+                            : s.refcount->vtable->hash(s.refcount, s);
+}
+
 grpc_slice grpc_slice_intern(grpc_slice slice) {
   interned_slice_refcount *s;
   uint32_t hash = gpr_murmur_hash3(GRPC_SLICE_START_PTR(slice),
@@ -168,8 +190,7 @@ grpc_slice grpc_slice_intern(grpc_slice slice) {
   gpr_atm_rel_store(&s->refcnt, 1);
   s->length = GRPC_SLICE_LENGTH(slice);
   s->hash = hash;
-  s->base.ref = interned_slice_ref;
-  s->base.unref = interned_slice_unref;
+  s->base.vtable = &interned_slice_vtable;
   s->bucket_next = shard->strs[idx];
   shard->strs[idx] = s;
   memcpy(s + 1, GRPC_SLICE_START_PTR(slice), GRPC_SLICE_LENGTH(slice));

src/core/lib/transport/static_metadata.c

@@ -114,10 +114,12 @@ static uint8_t g_raw_bytes[] = {
 
 static void static_ref(void *unused) {}
 static void static_unref(grpc_exec_ctx *exec_ctx, void *unused) {}
-static grpc_slice_refcount g_refcnt = {static_ref, static_unref};
+static const grpc_slice_refcount_vtable static_vtable = {
+    static_ref, static_unref, grpc_slice_default_hash_impl};
+static grpc_slice_refcount g_refcnt = {&static_vtable};
 
 bool grpc_is_static_metadata_string(grpc_slice slice) {
-  return slice.refcount != NULL && slice.refcount->ref == static_ref;
+  return slice.refcount != NULL && slice.refcount->vtable == &static_vtable;
 }
 
 const grpc_slice grpc_static_slice_table[GRPC_STATIC_MDSTR_COUNT] = {

tools/codegen/core/gen_static_metadata.py

@@ -310,10 +310,11 @@ print >>C, 'static uint8_t g_raw_bytes[] = {%s};' % (','.join('%d' % ord(c) for
 print >>C
 print >>C, 'static void static_ref(void *unused) {}'
 print >>C, 'static void static_unref(grpc_exec_ctx *exec_ctx, void *unused) {}'
-print >>C, 'static grpc_slice_refcount g_refcnt = {static_ref, static_unref};'
+print >>C, 'static const grpc_slice_refcount_vtable static_vtable = {static_ref, static_unref, grpc_slice_default_hash_impl};';
+print >>C, 'static grpc_slice_refcount g_refcnt = {&static_vtable};'
 print >>C
 print >>C, 'bool grpc_is_static_metadata_string(grpc_slice slice) {'
-print >>C, '  return slice.refcount != NULL && slice.refcount->ref == static_ref;'
+print >>C, '  return slice.refcount != NULL && slice.refcount->vtable == &static_vtable;'
 print >>C, '}'
 print >>C
 print >>C, 'const grpc_slice grpc_static_slice_table[GRPC_STATIC_MDSTR_COUNT] = {'