server : do not normalize embeddings when there is no pooling

ggml-ci

common/common.cpp

@@ -1780,7 +1780,9 @@ void common_embd_normalize(const float * inp, float * out, int n, int embd_norm)
             break;
         case 0: // max absolute
             for (int i = 0; i < n; i++) {
-                if (sum < std::abs(inp[i])) sum = std::abs(inp[i]);
+                if (sum < std::abs(inp[i])) {
+                    sum = std::abs(inp[i]);
+                }
             }
             sum /= 32760.0; // make an int16 range
             break;

common/common.h

@@ -596,7 +596,8 @@ void common_kv_cache_dump_view_seqs(const llama_kv_cache_view & view, int row_si
 // Embedding utils
 //
 
-void common_embd_normalize(const float * inp, float * out, int n, int embd_norm = 2);
+// TODO: repace embd_norm with an enum
+void common_embd_normalize(const float * inp, float * out, int n, int embd_norm);
 
 float common_embd_similarity_cos(const float * embd1, const float * embd2, int n);
 

examples/gritlm/gritlm.cpp

@@ -75,7 +75,7 @@ static std::vector<std::vector<float>> encode(llama_context * ctx, const std::ve
         }
 
         std::vector<float> emb_norm(emb_unorm.size());
-        common_embd_normalize(emb_unorm.data(), emb_norm.data(), n_embd);
+        common_embd_normalize(emb_unorm.data(), emb_norm.data(), n_embd, 2);
         result.push_back(emb_norm);
 
 #ifdef GRIT_DEBUG

examples/retrieval/retrieval.cpp

@@ -107,7 +107,7 @@ static void batch_decode(llama_context * ctx, llama_batch & batch, float * outpu
         }
 
         float * out = output + batch.seq_id[i][0] * n_embd;
-        common_embd_normalize(embd, out, n_embd);
+        common_embd_normalize(embd, out, n_embd, 2);
     }
 }
 

examples/server/server.cpp

@@ -2059,8 +2059,14 @@ struct server_context {
                 continue;
             }
 
-            common_embd_normalize(embd, embd_res.data(), n_embd);
-            res->embedding.push_back(embd_res);
+            // normalize only when there is pooling
+            // TODO: configurable
+            if (llama_pooling_type(slot.ctx) != LLAMA_POOLING_TYPE_NONE) {
+                common_embd_normalize(embd, embd_res.data(), n_embd, 2);
+                res->embedding.push_back(embd_res);
+            } else {
+                res->embedding.push_back({ embd, embd + n_embd });
+            }
         }
 
         SLT_DBG(slot, "%s", "sending embeddings\n");

examples/server/tests/unit/test_embedding.py

@@ -87,6 +87,10 @@ def test_embedding_pooling_none():
     assert 'embedding' in res.body[0]
     assert len(res.body[0]['embedding']) == 3
 
+    # make sure embedding vector is not normalized
+    for x in res.body[0]['embedding']:
+        assert abs(sum([x ** 2 for x in x]) - 1) > EPSILON
+
 
 def test_embedding_pooling_none_oai():
     global server
@@ -95,6 +99,7 @@ def test_embedding_pooling_none_oai():
     res = server.make_request("POST", "/v1/embeddings", data={
         "input": "hello hello hello",
     })
+
     # /v1/embeddings does not support pooling type 'none'
     assert res.status_code == 400