Move FetcherConfigs creation logic into FetcherConfigs

Bug: b/469552996

Author: Databean

base/cvd/cuttlefish/host/commands/assemble_cvd/assemble_cvd.cc

@@ -66,24 +66,6 @@
 namespace cuttlefish {
 namespace {
 
-static constexpr std::string_view kFetcherConfigFile = "fetcher_config.json";
-
-FetcherConfigs FindFetcherConfigs(
-    const SystemImageDirFlag& system_image_dir) {
-  std::vector<FetcherConfig> fetcher_configs;
-  for (size_t i = 0; i < system_image_dir.Size(); ++i) {
-    std::string fetcher_file =
-        fmt::format("{}/{}", system_image_dir.ForIndex(i), kFetcherConfigFile);
-    FetcherConfig fetcher_config;
-    if (!fetcher_config.LoadFromFile(fetcher_file)) {
-      LOG(DEBUG) << "No valid fetcher_config in '" << fetcher_file
-                 << "', falling back to default";
-    }
-    fetcher_configs.emplace_back(std::move(fetcher_config));
-  }
-  return FetcherConfigs::Create(std::move(fetcher_configs));
-}
-
 std::string GetLegacyConfigFilePath(const CuttlefishConfig& config) {
   return config.ForDefaultInstance().PerInstancePath("cuttlefish_config.json");
 }
@@ -606,7 +588,8 @@ Result<int> AssembleCvdMain(int argc, char** argv) {
   SystemImageDirFlag system_image_dir =
       CF_EXPECT(SystemImageDirFlag::FromGlobalGflags());
 
-  FetcherConfigs fetcher_configs = FindFetcherConfigs(system_image_dir);
+  FetcherConfigs fetcher_configs =
+      FetcherConfigs::ReadFromDirectories(system_image_dir.AsVector());
 
   InitramfsPathFlag initramfs_path =
       InitramfsPathFlag::FromGlobalGflags(fetcher_configs);

base/cvd/cuttlefish/host/commands/assemble_cvd/flags/system_image_dir.cc

@@ -55,6 +55,10 @@ std::string SystemImageDirFlag::ForIndex(size_t argument_index) const {
   return system_image_dirs_[argument_index];
 }
 
+const std::vector<std::string>& SystemImageDirFlag::AsVector() const {
+  return system_image_dirs_;
+}
+
 SystemImageDirFlag::SystemImageDirFlag(
     std::vector<std::string> system_image_dirs)
     : system_image_dirs_(std::move(system_image_dirs)) {}

base/cvd/cuttlefish/host/commands/assemble_cvd/flags/system_image_dir.h

@@ -34,6 +34,8 @@ class SystemImageDirFlag {
 
   size_t Size() const { return system_image_dirs_.size(); }
 
+  const std::vector<std::string>& AsVector() const;
+
  private:
   explicit SystemImageDirFlag(std::vector<std::string> system_image_dirs);
 

base/cvd/cuttlefish/host/libs/config/BUILD.bazel

@@ -226,6 +226,8 @@ cf_cc_library(
     hdrs = ["fetcher_configs.h"],
     deps = [
         "//cuttlefish/host/libs/config:fetcher_config",
+        "//libbase",
+        "@abseil-cpp//absl/strings",
     ],
 )
 

base/cvd/cuttlefish/host/libs/config/fetcher_configs.cc

@@ -18,17 +18,38 @@
 
 #include <stddef.h>
 
+#include <string>
+#include <string_view>
 #include <utility>
 #include <vector>
 
+#include "absl/strings/str_cat.h"
+#include "android-base/logging.h"
+
 #include "cuttlefish/host/libs/config/fetcher_config.h"
 
 namespace cuttlefish {
 
-FetcherConfigs FetcherConfigs::Create(std::vector<FetcherConfig> configs) {
+static constexpr std::string_view kFetcherConfigFile = "fetcher_config.json";
+
+FetcherConfigs FetcherConfigs::ReadFromDirectories(
+    const std::vector<std::string>& directories) {
+  std::vector<FetcherConfig> configs;
+  configs.reserve(directories.size());
+
+  for (std::string_view directory : directories) {
+    FetcherConfig& config = configs.emplace_back();
+
+    std::string config_path = absl::StrCat(directory, "/", kFetcherConfigFile);
+    if (!config.LoadFromFile(config_path)) {
+      LOG(DEBUG) << "No valid fetcher_config in '" << config_path
+                 << "', falling back to default";
+    }
+  }
   if (configs.empty()) {
     configs.emplace_back();
   }
+
   return FetcherConfigs(std::move(configs));
 }
 

base/cvd/cuttlefish/host/libs/config/fetcher_configs.h

@@ -17,6 +17,7 @@
 
 #include <stddef.h>
 
+#include <string>
 #include <vector>
 
 #include "cuttlefish/host/libs/config/fetcher_config.h"
@@ -25,7 +26,7 @@ namespace cuttlefish {
 
 class FetcherConfigs {
  public:
-  static FetcherConfigs Create(std::vector<FetcherConfig> configs);
+  static FetcherConfigs ReadFromDirectories(const std::vector<std::string>&);
   FetcherConfigs(FetcherConfigs&&) = default;
   ~FetcherConfigs() = default;