server: (router) add model management API (#23976)

* wip

* server: (router) add SSE realtime updates API

* nits

* wip

* add download API

* add download api

* update docs

* add delete endpoint

* fix std::terminate

* fix crash

* fix 2

* add tests

* nits

common/download.cpp

@@ -997,3 +997,87 @@ std::vector<common_cached_model_info> common_list_cached_models() {
 
     return result;
 }
+
+bool common_download_remove(const std::string & hf_repo_with_tag) {
+    namespace fs = std::filesystem;
+
+    auto [repo_id, tag] = common_download_split_repo_tag(hf_repo_with_tag);
+
+    if (tag.empty()) {
+        return hf_cache::remove_cached_repo(repo_id);
+    }
+
+    std::string tag_upper = tag;
+    for (char & c : tag_upper) {
+        c = (char) std::toupper((unsigned char) c);
+    }
+
+    auto files = hf_cache::get_cached_files(repo_id);
+    if (files.empty()) {
+        return false;
+    }
+
+    // collect snapshot entries whose tag matches
+    std::vector<fs::path> to_remove;
+    for (const auto & f : files) {
+        auto split = get_gguf_split_info(f.path);
+        if (split.tag == tag_upper) {
+            to_remove.emplace_back(f.local_path);
+        }
+    }
+
+    if (to_remove.empty()) {
+        return false;
+    }
+
+    // resolve blob paths from symlinks before deleting snapshot entries
+    std::vector<fs::path> blobs_to_check;
+    for (const auto & p : to_remove) {
+        std::error_code ec;
+        if (fs::is_symlink(p, ec)) {
+            auto target = fs::read_symlink(p, ec);
+            if (!ec) {
+                blobs_to_check.push_back((p.parent_path() / target).lexically_normal());
+            }
+        }
+    }
+
+    // remove snapshot entries
+    for (const auto & p : to_remove) {
+        std::error_code ec;
+        fs::remove(p, ec);
+        if (ec) {
+            LOG_WRN("%s: failed to remove %s: %s\n", __func__, p.string().c_str(), ec.message().c_str());
+        }
+    }
+
+    if (blobs_to_check.empty()) {
+        return true;
+    }
+
+    // collect blobs still referenced by remaining snapshot entries
+    std::unordered_set<std::string> still_referenced;
+    for (const auto & f : hf_cache::get_cached_files(repo_id)) {
+        fs::path p(f.local_path);
+        std::error_code ec;
+        if (fs::is_symlink(p, ec)) {
+            auto target = fs::read_symlink(p, ec);
+            if (!ec) {
+                still_referenced.insert((p.parent_path() / target).lexically_normal().string());
+            }
+        }
+    }
+
+    // remove orphaned blobs
+    for (const auto & blob : blobs_to_check) {
+        if (still_referenced.find(blob.string()) == still_referenced.end()) {
+            std::error_code ec;
+            fs::remove(blob, ec);
+            if (ec) {
+                LOG_WRN("%s: failed to remove blob %s: %s\n", __func__, blob.string().c_str(), ec.message().c_str());
+            }
+        }
+    }
+
+    return true;
+}

common/download.h

@@ -115,3 +115,10 @@ int common_download_file_single(const std::string & url,
 // resolve and download model from Docker registry
 // return local path to downloaded model file
 std::string common_docker_resolve_model(const std::string & docker);
+
+// Remove a cached model from disk
+// input format: "user/model" or "user/model:tag"
+// - if tag is omitted, removes the entire repo cache directory
+// - if tag is present, removes only files matching that tag (and orphaned blobs)
+// returns true if anything was removed
+bool common_download_remove(const std::string & hf_repo_with_tag);

common/hf-cache.cpp

@@ -495,4 +495,19 @@ std::string finalize_file(const hf_file & file) {
     return file.final_path;
 }
 
+bool remove_cached_repo(const std::string & repo_id) {
+    if (!is_valid_repo_id(repo_id)) {
+        LOG_WRN("%s: invalid repository: %s\n", __func__, repo_id.c_str());
+        return false;
+    }
+    fs::path repo_path = get_repo_path(repo_id);
+    std::error_code ec;
+    auto removed = fs::remove_all(repo_path, ec);
+    if (ec) {
+        LOG_ERR("%s: failed to remove repo cache %s: %s\n", __func__, repo_path.string().c_str(), ec.message().c_str());
+        return false;
+    }
+    return removed > 0;
+}
+
 } // namespace hf_cache

common/hf-cache.h

@@ -29,4 +29,7 @@ hf_files get_cached_files(const std::string & repo_id = {});
 // Create snapshot path (link or move/copy) and return it
 std::string finalize_file(const hf_file & file);
 
+// Remove the entire cached directory for a repo, returns true if removed
+bool remove_cached_repo(const std::string & repo_id);
+
 } // namespace hf_cache