server: add dedup-cache-models preset option (#27346)

common/arg.cpp

@@ -4658,6 +4658,12 @@ void common_params_add_preset_options(std::vector<common_arg> & args) {
         [](common_params &, int) { /* unused */ }
     ).set_env(COMMON_ARG_PRESET_STOP_TIMEOUT).set_preset_only());
 
+    args.push_back(common_arg(
+        {"dedup-cache-models"}, "0|1",
+        "in server router mode, hide a cached model from the model list when this preset resolves to the same model file",
+        [](common_params &, const std::string &) { /* unused */ }
+    ).set_env(COMMON_ARG_PRESET_DEDUP_CACHE_MODELS).set_preset_only());
+
     // args.push_back(common_arg(
     //     {"pin"},
     //     "in server router mode, do not unload this model if models_max is exceeded",

common/arg.h

@@ -11,8 +11,9 @@
 #include <memory>
 
 // pseudo-env variable to identify preset-only arguments
-#define COMMON_ARG_PRESET_LOAD_ON_STARTUP "__PRESET_LOAD_ON_STARTUP"
-#define COMMON_ARG_PRESET_STOP_TIMEOUT    "__PRESET_STOP_TIMEOUT"
+#define COMMON_ARG_PRESET_LOAD_ON_STARTUP    "__PRESET_LOAD_ON_STARTUP"
+#define COMMON_ARG_PRESET_STOP_TIMEOUT       "__PRESET_STOP_TIMEOUT"
+#define COMMON_ARG_PRESET_DEDUP_CACHE_MODELS "__PRESET_DEDUP_CACHE_MODELS"
 
 //
 // CLI argument parsing

common/download.cpp

@@ -989,6 +989,26 @@ std::vector<common_cached_model_info> common_list_cached_models() {
     return result;
 }
 
+std::string common_download_resolve_path(const std::string & hf_repo_with_tag, const std::string & hf_file) {
+    auto [repo, tag] = common_download_split_repo_tag(hf_repo_with_tag);
+
+    auto files = hf_cache::get_cached_files(repo);
+    if (files.empty()) {
+        return "";
+    }
+
+    if (!hf_file.empty()) {
+        for (const auto & f : files) {
+            if (f.path == hf_file) {
+                return f.local_path;
+            }
+        }
+        return "";
+    }
+
+    return find_best_model(files, tag).local_path;
+}
+
 bool common_download_remove(const std::string & hf_repo_with_tag) {
     namespace fs = std::filesystem;
 

common/download.h

@@ -85,6 +85,10 @@ std::vector<std::string> common_download_get_all_parts(const std::string & url);
 // returns list of cached models
 std::vector<common_cached_model_info> common_list_cached_models();
 
+// resolve the local cached file path for a HF repo without network access (hf_file, if given, must match exactly)
+// returns an empty string if the model is not present in the cache
+std::string common_download_resolve_path(const std::string & hf_repo_with_tag, const std::string & hf_file = "");
+
 // download single file from url to local path
 // returns status code or -1 on error
 // skip_etag: if true, don't read/write .etag files (for HF cache where filename is the hash)