add --reranking argument

Author: ngxson

common/arg.cpp

@@ -284,6 +284,10 @@ static bool gpt_params_parse_ex(int argc, char ** argv, gpt_params_context & ctx
         params.kv_overrides.back().key[0] = 0;
     }
 
+    if (params.reranking && params.embedding) {
+        throw std::invalid_argument("error: either --embedding or --reranking can be specified, but not both");
+    }
+
     return true;
 }
 
@@ -1750,6 +1754,13 @@ gpt_params_context gpt_params_parser_init(gpt_params & params, llama_example ex,
             params.embedding = true;
         }
     ).set_examples({LLAMA_EXAMPLE_SERVER}).set_env("LLAMA_ARG_EMBEDDINGS"));
+    add_opt(llama_arg(
+        {"--reranking", "--rerank"},
+        format("enable reranking endpoint on server (default: %s)", params.reranking ? "enabled" : "disabled"),
+        [](gpt_params & params) {
+            params.reranking = true;
+        }
+    ).set_examples({LLAMA_EXAMPLE_SERVER}).set_env("LLAMA_ARG_RERANKING"));
     add_opt(llama_arg(
         {"--api-key"}, "KEY",
         "API key to use for authentication (default: none)",

common/common.cpp

@@ -1023,6 +1023,11 @@ struct llama_context_params llama_context_params_from_gpt_params(const gpt_param
     cparams.flash_attn        = params.flash_attn;
     cparams.no_perf           = params.no_perf;
 
+    if (params.reranking) {
+        cparams.embeddings    = true;
+        cparams.pooling_type  = LLAMA_POOLING_TYPE_RANK;
+    }
+
     cparams.type_k = kv_cache_type_from_str(params.cache_type_k);
     cparams.type_v = kv_cache_type_from_str(params.cache_type_v);
 

common/common.h

@@ -271,6 +271,7 @@ struct gpt_params {
     int32_t embd_normalize = 2;     // normalisation for embendings (-1=none, 0=max absolute int16, 1=taxicab, 2=euclidean, >2=p-norm)
     std::string embd_out   = "";    // empty = default, "array" = [[],[]...], "json" = openai style, "json+" = same "json" + cosine similarity matrix
     std::string embd_sep   = "\n";  // separator of embendings
+    bool reranking         = false; // enable reranking support on server
 
     // server params
     int32_t port           = 8080;         // server listens on this network port

examples/server/server.cpp

@@ -2888,8 +2888,8 @@ int main(int argc, char ** argv) {
     };
 
     const auto handle_completions_generic = [&ctx_server, &res_error, &res_ok](server_task_cmpl_type cmpl_type, json & data, httplib::Response & res) {
-        if (ctx_server.params.embedding) {
-            res_error(res, format_error_response("This server does not support completions. Start it without `--embeddings`", ERROR_TYPE_NOT_SUPPORTED));
+        if (ctx_server.params.embedding || ctx_server.params.reranking) {
+            res_error(res, format_error_response("This server does not support completions. Start it without `--embeddings` or `--reranking`", ERROR_TYPE_NOT_SUPPORTED));
             return;
         }
 
@@ -2949,8 +2949,8 @@ int main(int argc, char ** argv) {
 
     // TODO: maybe merge this function with "handle_completions_generic"
     const auto handle_chat_completions = [&ctx_server, &params, &res_error, &res_ok, verbose](const httplib::Request & req, httplib::Response & res) {
-        if (ctx_server.params.embedding) {
-            res_error(res, format_error_response("This server does not support completions. Start it without `--embeddings`", ERROR_TYPE_NOT_SUPPORTED));
+        if (ctx_server.params.embedding || ctx_server.params.reranking) {
+            res_error(res, format_error_response("This server does not support completions. Start it without `--embeddings` or `--reranking`", ERROR_TYPE_NOT_SUPPORTED));
             return;
         }
 
@@ -3074,6 +3074,11 @@ int main(int argc, char ** argv) {
     };
 
     const auto handle_embeddings = [&ctx_server, &res_error, &res_ok](const httplib::Request & req, httplib::Response & res) {
+        // TODO: somehow clean up this checks in the future
+        if (!ctx_server.params.embedding || ctx_server.params.reranking) {
+            res_error(res, format_error_response("This server does not support embeddings. Start it with `--embeddings` and without `--reranking`", ERROR_TYPE_NOT_SUPPORTED));
+            return;
+        }
         const json body = json::parse(req.body);
         bool is_openai = false;
 
@@ -3125,6 +3130,10 @@ int main(int argc, char ** argv) {
     };
 
     const auto handle_rerank = [&ctx_server, &res_error, &res_ok](const httplib::Request & req, httplib::Response & res) {
+        if (!ctx_server.params.reranking) {
+            res_error(res, format_error_response("This server does not support reranking. Start it with `--reranking`", ERROR_TYPE_NOT_SUPPORTED));
+            return;
+        }
         const json body = json::parse(req.body);
 
         // TODO: implement
@@ -3148,15 +3157,9 @@ int main(int argc, char ** argv) {
             return;
         }
 
-        json documents;
-        if (body.count("documents") != 0) {
-            documents = body.at("documents");
-            if (!documents.is_array() || documents.size() == 0) {
-                res_error(res, format_error_response("\"documents\" must be a non-empty string array", ERROR_TYPE_INVALID_REQUEST));
-                return;
-            }
-        } else {
-            res_error(res, format_error_response("\"documents\" must be provided", ERROR_TYPE_INVALID_REQUEST));
+        std::vector<std::string> documents = json_value(body, "documents", std::vector<std::string>());
+        if (documents.empty()) {
+            res_error(res, format_error_response("\"documents\" must be a non-empty string array", ERROR_TYPE_INVALID_REQUEST));
             return;
         }
 

examples/server/tests/features/embeddings.feature

@@ -15,7 +15,7 @@ Feature: llama.cpp server
     And   128 as batch size
     And   128 as ubatch size
     And   512 KV cache size
-    And   embeddings extraction
+    And   enable embeddings endpoint
     Then  the server is starting
     Then  the server is healthy
 

examples/server/tests/features/rerank.feature

@@ -12,7 +12,7 @@ Feature: llama.cpp server
     And   512 as batch size
     And   512 as ubatch size
     And   512 KV cache size
-    And   embeddings extraction
+    And   enable reranking endpoint
     Then  the server is starting
     Then  the server is healthy
 
@@ -39,5 +39,4 @@ Feature: llama.cpp server
       """
     When  reranking request
     Then  reranking results are returned
-    # TODO: this result make no sense, probably need a better model?
-    Then  reranking highest score is index 3 and lowest score is index 0
+    Then  reranking highest score is index 2 and lowest score is index 3

examples/server/tests/features/steps/steps.py

@@ -68,6 +68,7 @@ def step_server_config(context, server_fqdn: str, server_port: str):
     context.server_api_key = None
     context.server_continuous_batching = False
     context.server_embeddings = False
+    context.server_reranking = False
     context.server_metrics = False
     context.server_process = None
     context.seed = None
@@ -176,10 +177,13 @@ def step_server_continuous_batching(context):
     context.server_continuous_batching = True
 
 
-@step('embeddings extraction')
+@step('enable embeddings endpoint')
 def step_server_embeddings(context):
     context.server_embeddings = True
 
+@step('enable reranking endpoint')
+def step_server_reranking(context):
+    context.server_reranking = True
 
 @step('prometheus compatible metrics exposed')
 def step_server_metrics(context):
@@ -1408,6 +1412,8 @@ def start_server_background(context):
         server_args.append('--cont-batching')
     if context.server_embeddings:
         server_args.append('--embedding')
+    if context.server_reranking:
+        server_args.append('--reranking')
     if context.server_metrics:
         server_args.append('--metrics')
     if context.model_alias: