Add wasm64 builds to CI and publish

.github/actions/install-deps/action.yaml

@@ -41,6 +41,9 @@ inputs:
     skip_cache:
         default: "false"
         description: "Don't use cache from previous builds"
+    ccache:
+        default: ""
+        description: "Install ccache with this cache key (empty = disabled); build steps must also set PSP_USE_CCACHE"
 
 runs:
     using: "composite"
@@ -115,11 +118,12 @@ runs:
               restore-keys: |
                   ${{ runner.os }}-cargo-
 
-        # - name: ccache
-        #   uses: hendrikmuhs/ccache-action@v1.2
-        #   if: ${{ inputs.skip_cache == 'false' }}
-        #   with:
-        #       key: ${{ github.job }}-${{ matrix.os }}
+        - name: ccache
+          uses: hendrikmuhs/ccache-action@v1.2
+          if: ${{ inputs.ccache != '' && inputs.skip_cache == 'false' }}
+          with:
+              key: ${{ inputs.ccache }}
+              max-size: "1G"
 
         # https://github.com/apache/arrow/issues/38391
         - if: ${{ runner.os == 'macOS' }}

.github/workflows/build.yaml

@@ -147,13 +147,14 @@ jobs:
                   clean: "true"
                   python: "false"
                   playwright: "true"
+                  ccache: "emscripten-wasm32"
                   skip_cache: ${{ steps.config-step.outputs.SKIP_CACHE }}
 
             - name: WebAssembly Build
               run: pnpm run build --ci
               env:
                   PACKAGE: "server,client,viewer,viewer-datagrid,viewer-charts,react,anywidget"
-                  # PSP_USE_CCACHE: 1
+                  PSP_USE_CCACHE: "1"
 
             - uses: actions/upload-artifact@v4
               with:
@@ -179,6 +180,56 @@ jobs:
                       rust/perspective-python/perspective/widget/static/perspective-anywidget.js
                       rust/perspective-python/perspective/widget/static/perspective-anywidget.css
 
+    # The Memory64 engine recompiles the entire C++ dependency chain under
+    # `-sMEMORY64` (no object sharing with wasm32 is possible), so it builds
+    # on its own runner in parallel with `build_js` rather than doubling that
+    # job's wall clock. Downstream jobs merge this single-file artifact into
+    # `rust/perspective-server/dist/wasm/`.
+    build_js_wasm64:
+        runs-on: ${{ matrix.os }}
+        needs: [lint_and_docs]
+        strategy:
+            fail-fast: false
+            matrix:
+                os:
+                    - ubuntu-22.04
+                node-version: [22.x]
+
+        steps:
+            - name: Checkout
+              uses: actions/checkout@v4
+
+            - name: Config
+              id: config-step
+              uses: ./.github/actions/config
+
+            - uses: actions/download-artifact@v4
+              with:
+                  name: perspective-metadata
+                  path: rust/
+
+            - name: Initialize Build
+              id: init-step
+              uses: ./.github/actions/install-deps
+              with:
+                  clean: "true"
+                  python: "false"
+                  playwright: "true"
+                  ccache: "emscripten-wasm64"
+                  skip_cache: ${{ steps.config-step.outputs.SKIP_CACHE }}
+
+            - name: WebAssembly Build (Memory64)
+              run: pnpm run build --ci
+              env:
+                  PACKAGE: "server"
+                  PSP_WASM64: "only"
+                  PSP_USE_CCACHE: "1"
+
+            - uses: actions/upload-artifact@v4
+              with:
+                  name: perspective-server-wasm64-dist
+                  path: rust/perspective-server/dist/wasm/perspective-server.memory64.wasm
+
     # ,-,---.       .    .  .-,--.     .  .
     #  '|___/ . . . |  ,-|   '|__/ . . |- |-. ,-. ,-.
     #  ,|   \ | | | |  | |   ,|    | | |  | | | | | |
@@ -654,7 +705,7 @@ jobs:
     #                   /` |                              |
     #                   `--'                              '
     test_js:
-        needs: [build_js]
+        needs: [build_js, build_js_wasm64]
         runs-on: ${{ matrix.os }}
         strategy:
             fail-fast: false
@@ -687,6 +738,11 @@ jobs:
                   name: perspective-js-dist
                   path: .
 
+            - uses: actions/download-artifact@v4
+              with:
+                  name: perspective-server-wasm64-dist
+                  path: rust/perspective-server/dist/wasm
+
             - name: Run Tests
               id: run_tests
               run: pnpm run test -- --fetch-snapshots
@@ -989,6 +1045,7 @@ jobs:
         needs:
             [
                 build_and_test_jupyterlab,
+                build_js_wasm64,
                 test_python,
                 test_python_sdist,
                 test_js,
@@ -1068,6 +1125,16 @@ jobs:
             - run: pnpm pack --pack-destination=../..
               working-directory: ./rust/perspective-js
 
+            - uses: actions/download-artifact@v4
+              with:
+                  name: perspective-server-wasm64-dist
+                  path: rust/perspective-server/dist/wasm
+
+            # `files` globs don't fail on absence, so a silently-skipped
+            # memory64 build would otherwise publish a wasm32-only package.
+            - name: Assert wasm64 engine asset
+              run: test -f rust/perspective-server/dist/wasm/perspective-server.memory64.wasm
+
             - run: pnpm pack --pack-destination=../..
               working-directory: ./rust/perspective-server
 

docs/md/how_to/javascript/importing.md

@@ -36,6 +36,23 @@ const viewer = document.createElement("perspective-viewer");
 
 The exact syntax will vary slightly depending on the bundler.
 
+### Memory64 (wasm64)
+
+`@perspective-dev/server` also ships a WebAssembly Memory64 build of the
+engine, `dist/wasm/perspective-server.memory64.wasm`, which raises the
+engine's heap ceiling from 4GB to 16GB (at some engine performance cost).
+`init_server` accepts both binaries at once — register each as a _thunk_ and
+only the selected binary is ever downloaded. The wasm64 binary is used
+whenever the browser supports Memory64; registering only the wasm32 binary
+(as above) opts out.
+
+```javascript
+perspective.init_server({
+    wasm32: () => fetch(SERVER_WASM),
+    wasm64: () => fetch(SERVER_WASM64),
+});
+```
+
 ### Vite
 
 ```javascript