Use GZIP magic bytes to detect whether a file is compressed

lab-cosmo · Aug 30, 2024 · 7919906 · 7919906
1 parent 2e2d352
commit 7919906
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Showing 2 changed files with 31 additions and 22 deletions.
diff --git a/app/app.ts b/app/app.ts
@@ -125,7 +125,7 @@ export class ChemiscopeApp {
             }
         }
 
-        const dataset = readJSON(this.dataset, buffer);
+        const dataset = readJSON(buffer);
         await this.load(config as Configuration, dataset);
     }
 
@@ -204,7 +204,7 @@ export class ChemiscopeApp {
             const file = loadDataset.files![0];
             this.dataset = file.name;
             readFile(file, (result) => {
-                const dataset = readJSON(file.name, result);
+                const dataset = readJSON(result);
                 this.load({}, dataset);
                 // clear the selected file name to make sure 'onchange' is
                 // called again if the user loads a file a the same path
@@ -242,7 +242,7 @@ export class ChemiscopeApp {
                     return;
                 }
 
-                this.visualizer.applySettings(readJSON(file.name, result));
+                this.visualizer.applySettings(readJSON(result));
                 // clear the selected file name to make sure 'onchange' is
                 // called again if the user loads a file a the same path
                 // multiple time
@@ -307,9 +307,12 @@ function stopLoading() {
 }
 
 /** Read JSON or gzipped JSON and return the parsed object */
-function readJSON(path: string, buffer: ArrayBuffer): any {
+function readJSON(buffer: ArrayBuffer): any {
+    const magic = new Uint8Array(buffer.slice(0, 2));
+
     let text;
-    if (path.endsWith('.gz')) {
+    // '1f 8b' is the magic constant starting gzip files
+    if (magic[0] == 0x1f && magic[1] == 0x8b) {
         text = inflate(new Uint8Array(buffer), { to: 'string' });
     } else {
         const decoder = new TextDecoder('utf-8');

diff --git a/python/chemiscope/sphinx/static/chemiscope-sphinx.js b/python/chemiscope/sphinx/static/chemiscope-sphinx.js
@@ -1,10 +1,12 @@
+/* eslint-disable */
+
 /**
  * Enum of the modes
  */
 const VISUALISER_MODE = {
-    DEFAULT: "default",
-    STRUCTURE: "structure",
-    MAP: "map"
+    DEFAULT: 'default',
+    STRUCTURE: 'structure',
+    MAP: 'map',
 };
 
 /**
@@ -35,15 +37,12 @@ async function loadChemiscopeSphinx(divId, filePath, visualizerMode = VISUALISER
         // Load widget
         const visualiser = getVisualizer(visualizerMode);
         await visualiser.load(config, dataset);
-    }
-
-    // Display errors
-    catch (error) {
+    } catch (error) {
+        // Display errors
+        console.error(error);
         displayWarning(divId, error);
-    }
-
-    // Hide loading
-    finally {
+    } finally {
+        // Hide loading
         toggleLoadingVisible(divId, false);
     }
 }
@@ -74,11 +73,18 @@ async function fetchDataset(filePath) {
     if (!response.ok) {
         throw new Error(`Failed to fetch ${filePath}: ${response.statusText}`);
     }
-
-    // Get as json
     const buffer = await response.arrayBuffer();
-    const decompressedData = pako.inflate(new Uint8Array(buffer), { to: 'string' });
-    return parseJsonWithNaN(decompressedData);
+    const magic = new Uint8Array(buffer.slice(0, 2));
+
+    let text;
+    // '1f 8b' is the magic constant starting gzip files
+    if (magic[0] == 0x1f && magic[1] == 0x8b) {
+        text = pako.inflate(new Uint8Array(buffer), { to: 'string' });
+    } else {
+        const decoder = new TextDecoder('utf-8');
+        text = decoder.decode(buffer);
+    }
+    return parseJsonWithNaN(text);
 }
 
 /**
@@ -141,7 +147,7 @@ function generateChemiscopeHTML(config, visualizerMode) {
 function toggleLoadingVisible(divId, visible = true) {
     const loader = document.getElementById(`${divId}-loading`);
     if (loader) {
-        loader.style.display = visible ? "block" : "none";
+        loader.style.display = visible ? 'block' : 'none';
     }
 }
 
@@ -151,7 +157,7 @@ function toggleLoadingVisible(divId, visible = true) {
 function hideElement(elementId) {
     const element = document.getElementById(elementId);
     if (element) {
-        element.style.display = "none";
+        element.style.display = 'none';
     } else {
         console.error(`Element ${elementId} is not found`);
     }