reuse intermediate deno caches

flake.nix

@@ -10,10 +10,7 @@
     flake-utils.lib.eachDefaultSystem (system:
       let
         pkgs = nixpkgs.legacyPackages.${system};
-        lib = {
+        lib = import ./nix/deno;
-          collectDenoCaches = import ./nix/deno/collect_caches.nix;
-          readDenoScroll = import ./nix/deno/read_scroll.nix;
-        };
         shelf = import ./shelf {
           inherit pkgs system lib;
         };

nix/deno/buildDenoCache.nix

@@ -0,0 +1,76 @@
+{ self }:
+{ pkgs, system, scrollsDir, subDir, baseCache ? null }:
+let
+  target =
+    let
+      arch = builtins.head (builtins.split "-" system);
+      os = builtins.elemAt (builtins.split "-" system) 1;
+      vendor = if os == "darwin" then "apple" else "unknown";
+      sys = if os == "darwin" then "darwin" else "linux-gnu";
+    in "${arch}-${vendor}-${sys}";
+
+  scroll = import "${scrollsDir}/${subDir}/scroll.nix";
+  
+  hashFilesCat = builtins.concatStringsSep ""
+    (builtins.map builtins.readFile scroll.build.hashFiles);
+  sourceContentHash_ = builtins.convertHash {
+    hash = "sha1:${builtins.hashString "sha1" hashFilesCat}";
+    toHashFormat = "base64";
+  };
+  sourceContentHash = "sha1-${sourceContentHash_}";
+  outputHash =
+    scroll.build.knownHashes.${sourceContentHash}
+      or pkgs.lib.fakeSha256;
+
+in
+pkgs.stdenv.mkDerivation {
+  name = if baseCache == null 
+    then "${scroll.name}-scroll-env" 
+    else "${scroll.name}-incremental-cache";
+  src = scrollsDir;
+
+  nativeBuildInputs = [ pkgs.deno pkgs.jq ];
+  dontPatchShebangs = true;
+
+  buildPhase = ''
+    export DENO_DIR=$out
+    mkdir -p $DENO_DIR
+
+    # Start with base cache if provided
+    ${if baseCache != null then ''
+      if [ -d "${baseCache}" ]; then
+        cp -r "${baseCache}"/* "$out/" 2>/dev/null || true
+        find "$out" -type f -exec chmod u+w {} \;
+        find "$out" -type d -exec chmod u+w {} \;
+      fi
+    '' else ""}
+
+    cd ${subDir}
+    echo "Building cache for ${scroll.name}..."
+    ${scroll.build.cacheCommand}
+    cd ..
+
+    echo 'Go fuck yourself, SQLite!'
+    find $out -name "*-wal" -delete
+    find $out -name "*-shm" -delete
+
+    echo 'Go fuck yourself, JSON!'
+    find $out/npm -name "*.json" -type f 2>/dev/null | while read -r file; do
+      if ${pkgs.jq}/bin/jq empty "$file" 2>/dev/null; then
+        ${pkgs.jq}/bin/jq -S . "$file" > "$file.tmp" && mv "$file.tmp" "$file"
+      fi
+    done
+
+    echo 'sourceContentHash: ${sourceContentHash}'
+    echo ""
+    echo "add me to knownHashes if you see a fake sha256 error ^"
+    echo "DON'T USE JSR DEPS UNLESS YOU MAKE THEM REPRODUCIBLE SOMEHOW"
+    echo ""
+  '';
+
+  installPhase = "true";
+
+  outputHashMode = "recursive";
+  outputHashAlgo = "sha256";
+  inherit outputHash;
+}

nix/deno/buildSharedDenoCache.nix

@@ -0,0 +1,14 @@
+{ self }:
+{ pkgs, system, scrollsDir, subDirs }:
+let
+  emptyDenoCache = pkgs.runCommand "empty-deno-cache" {} ''
+    mkdir -p $out
+  '';
+
+in
+builtins.foldl' (accCache: subDir:
+  self.buildDenoCache { 
+    inherit pkgs system scrollsDir subDir;
+    baseCache = accCache; 
+  }
+) emptyDenoCache subDirs

nix/deno/collect_caches.nix

@@ -1,42 +0,0 @@
-{ pkgs, denoCacheDrvs }:
-let
-  mergeOneCache = cache: ''
-    if [ -d "${cache}" ]; then
-      echo "  Merging cache from ${cache}"
-      # Use cp with fallback, handle overlapping files gracefully
-      cp -rL "${cache}"/* "$out/" 2>/dev/null || true
-    else
-      echo "  Warning: ${cache} is not a directory, skipping"
-    fi
-  '';
-
-  mergeCacheCmd = pkgs.runCommand "deno-shelf-shared-cache"
-    {
-      buildInputs = denoCacheDrvs;
-    } ''
-    mkdir -p $out
-
-    echo "Merging ${builtins.toString (builtins.length denoCacheDrvs)} Deno caches..."
-
-    ${pkgs.lib.concatMapStringsSep "\n" mergeOneCache denoCacheDrvs}
-
-    echo "Deno caches merged. Final size: $(du -sh $out | cut -f1)"
-  '';
-in
-
-pkgs.writeShellScript "deno-shelf-setup" ''
-  export DENO_DIR=$PWD/.deno_cache
-
-  if [ ! -d "$DENO_DIR" ] || [ "${mergeCacheCmd}" -nt "$DENO_DIR/.cache_timestamp" ]; then
-    echo "Setting up mutable Deno cache..."
-
-    rm -rf "$DENO_DIR"
-    cp -r "${mergeCacheCmd}" "$DENO_DIR"
-    chmod -R u+w "$DENO_DIR"
-
-    touch "$DENO_DIR/.cache_timestamp"
-    echo "Deno cache initialized"
-  else
-    echo "Deno cache already up to date"
-  fi
-''

nix/deno/default.nix

@@ -0,0 +1,9 @@
+let
+  lib = {
+    buildDenoCache = import ./buildDenoCache.nix { self = lib; };
+    readDenoScroll = import ./readDenoScroll.nix { self = lib; };
+    buildSharedDenoCache = import ./buildSharedDenoCache.nix { self = lib; };
+    makeDenoShelfSetup = import ./makeDenoShelfSetup.nix { self = lib; };
+  };
+in
+lib

nix/deno/makeDenoShelfSetup.nix

@@ -0,0 +1,19 @@
+{ self }:
+{ pkgs, sharedCache }:
+
+pkgs.writeShellScript "deno-shelf-setup" ''
+  export DENO_DIR=$PWD/.deno_cache
+
+  if [ ! -d "$DENO_DIR" ] || [ "${sharedCache}" -nt "$DENO_DIR/.cache_timestamp" ]; then
+    echo "Setting up shared Deno cache..."
+
+    rm -rf "$DENO_DIR"
+    cp -r "${sharedCache}" "$DENO_DIR"
+    chmod -R u+w "$DENO_DIR"
+
+    touch "$DENO_DIR/.cache_timestamp"
+    echo "Shared Deno cache initialized"
+  else
+    echo "Deno cache is up to date"
+  fi
+''

nix/deno/readDenoScroll.nix

@@ -0,0 +1,11 @@
+{ self }:
+{ pkgs, system, scrollsDir, subDir }:
+let
+  scroll = import "${scrollsDir}/${subDir}/scroll.nix";
+in
+{
+  env = self.buildDenoCache {
+    inherit pkgs system scrollsDir subDir;
+  };
+  meta = builtins.removeAttrs scroll [ "build" ];
+}

nix/deno/read_scroll.nix

@@ -1,64 +0,0 @@
-{ pkgs, system, scrollsDir, subDir }:
-let
-  target =
-    let
-      arch = builtins.head (builtins.split "-" system);
-      os = builtins.elemAt (builtins.split "-" system) 1;
-      vendor = if os == "darwin" then "apple" else "unknown";
-      sys = if os == "darwin" then "darwin" else "linux-gnu";
-    in "${arch}-${vendor}-${sys}";
-
-  scroll = import "${scrollsDir}/${subDir}/scroll.nix";
-
-  hashFilesCat = builtins.concatStringsSep ""
-    (builtins.map builtins.readFile scroll.build.hashFiles);
-  sourceContentHash_ = builtins.convertHash {
-    hash = "sha1:${builtins.hashString "sha1" hashFilesCat}";
-    toHashFormat = "base64";
-  };
-  sourceContentHash = "sha1-${sourceContentHash_}";
-  outputHash =
-    scroll.build.knownHashes.${sourceContentHash}
-      or pkgs.lib.fakeSha256;
-in
-{
-  env = pkgs.stdenv.mkDerivation {
-    name = "${scroll.name}-scroll-env";
-    src = scrollsDir;
-
-    nativeBuildInputs = [ pkgs.deno pkgs.jq ];
-    dontPatchShebangs = true;
-
-    buildPhase = ''
-      export DENO_DIR=$out
-
-      cd ${subDir}
-      ${scroll.build.cacheCommand}
-      cd ..
-
-      echo 'Go fuck yourself, SQLite!'
-      find $out -name "*-wal" -delete
-      find $out -name "*-shm" -delete
-
-      echo 'Go fuck yourself, JSON!'
-      find $out/npm -name "*.json" -type f 2>/dev/null | while read -r file; do
-        if ${pkgs.jq}/bin/jq empty "$file" 2>/dev/null; then
-          ${pkgs.jq}/bin/jq -S . "$file" > "$file.tmp" && mv "$file.tmp" "$file"
-        fi
-      done
-
-      echo 'sourceContentHash: ${sourceContentHash}'
-      echo ""
-      echo "add me to knownHashes if you see a fake sha256 error ^"
-      echo "DON'T USE JSR DEPS UNLESS YOU MAKE THEM REPRODUCIBLE SOMEHOW"
-      echo ""
-    '';
-
-    installPhase = "true";
-
-    outputHashMode = "recursive";
-    outputHashAlgo = "sha256";
-    inherit outputHash;
-  };
-  meta = builtins.removeAttrs scroll [ "build" ];
-}

shelf/default.nix

@@ -7,19 +7,28 @@ let
     scrollsDir = denoScrollsDir;
   };
 
-  scrolls = builtins.map mkScroll [
+  scrollDirs = [
     "hjq"
     "uses-hjq"
   ];
   
-  shelfSetup =
+  scrolls = builtins.map mkScroll scrollDirs;
-    lib.collectDenoCaches {
+
-      inherit pkgs;
+  # shelfSetup =
-      denoCacheDrvs = builtins.map (s: s.env) scrolls;
+  #   lib.collectDenoCaches {
+  #     inherit pkgs;
+  #     denoCacheDrvs = builtins.map (s: s.env) scrolls;
+  #   };
+  sharedCache = lib.buildSharedDenoCache {
+    inherit pkgs system;
+    scrollsDir = denoScrollsDir;
+    subDirs = scrollDirs;
   };
 in
 {
-  setupScript = shelfSetup;
+  setupScript = lib.makeDenoShelfSetup {
+    inherit pkgs sharedCache;
+  };
 
   scrolls = builtins.map (s: s.meta) scrolls;
 }