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2026-06-17 05:36:17 +02:00 · 2020-10-04 17:14:00 +02:00
parent c0d3912413
commit 091f119048
4382 changed files with 1762543 additions and 9606 deletions
@@ -0,0 +1,165 @@
+var esprima = require('esprima');
+var escodegen = require('escodegen');
+var estraverse = require('estraverse');
+
+var SYNTAX = estraverse.Syntax;
+
+var STR_MIN_LENGTH = 5;
+var STR_MIN_DIST = 1000;
+var STR_MIN_COUNT = 2;
+
+function createDeclaration(declarations) {
+    return {
+        type: SYNTAX.VariableDeclaration,
+        declarations: declarations,
+        kind: 'var'
+    };
+}
+
+function createDeclarator(id, init) {
+    return {
+        type: SYNTAX.VariableDeclarator,
+        id: {
+            type: SYNTAX.Identifier,
+            name: id
+        },
+        init: {
+            type: SYNTAX.Literal,
+            value: init
+        }
+    };
+}
+
+function base54Digits() {
+    return 'etnrisouaflchpdvmgybwESxTNCkLAOM_DPHBjFIqRUzWXV$JKQGYZ0516372984';
+}
+
+var base54 = (function(){
+    var DIGITS = base54Digits();
+    return function(num) {
+        var ret = '';
+        var base = 54;
+        do {
+            ret += DIGITS.charAt(num % base);
+            num = Math.floor(num / base);
+            base = 64;
+        } while (num > 0);
+        return ret;
+    };
+})();
+
+function mangleString(source) {
+
+    var ast = esprima.parse(source, {
+        loc: true
+    });
+
+    var stringVariables = {};
+
+    var stringRelaceCount = 0;
+
+    estraverse.traverse(ast, {
+        enter: function (node, parent) {
+            if (node.type === SYNTAX.Literal
+                && typeof node.value === 'string'
+            ) {
+                // Ignore if string is the key of property
+                if (parent.type === SYNTAX.Property) {
+                    return;
+                }
+                var value = node.value;
+                if (value.length > STR_MIN_LENGTH) {
+                    if (!stringVariables[value]) {
+                        stringVariables[value] = {
+                            count: 0,
+                            lastLoc: node.loc.start.line,
+                            name: '__echartsString__' + base54(stringRelaceCount++)
+                        };
+                    }
+                    var diff = node.loc.start.line - stringVariables[value].lastLoc;
+                    // GZIP ?
+                    if (diff >= STR_MIN_DIST) {
+                        stringVariables[value].lastLoc = node.loc.start.line;
+                        stringVariables[value].count++;
+                    }
+                }
+            }
+
+            if (node.type === SYNTAX.MemberExpression && !node.computed) {
+                if (node.property.type === SYNTAX.Identifier) {
+                    var value = node.property.name;
+                    if (value.length > STR_MIN_LENGTH) {
+                        if (!stringVariables[value]) {
+                            stringVariables[value] = {
+                                count: 0,
+                                lastLoc: node.loc.start.line,
+                                name: '__echartsString__' + base54(stringRelaceCount++)
+                            };
+                        }
+                        var diff = node.loc.start.line - stringVariables[value].lastLoc;
+                        if (diff >= STR_MIN_DIST) {
+                            stringVariables[value].lastLoc = node.loc.start.line;
+                            stringVariables[value].count++;
+                        }
+                    }
+                }
+            }
+        }
+    });
+
+    estraverse.replace(ast, {
+        enter: function (node, parent) {
+            if ((node.type === SYNTAX.Literal
+                && typeof node.value === 'string')
+            ) {
+                // Ignore if string is the key of property
+                if (parent.type === SYNTAX.Property) {
+                    return;
+                }
+                var str = node.value;
+                if (stringVariables[str] && stringVariables[str].count > STR_MIN_COUNT) {
+                    return {
+                        type: SYNTAX.Identifier,
+                        name: stringVariables[str].name
+                    };
+                }
+            }
+            if (node.type === SYNTAX.MemberExpression && !node.computed) {
+                if (node.property.type === SYNTAX.Identifier) {
+                    var str = node.property.name;
+                    if (stringVariables[str] && stringVariables[str].count > STR_MIN_COUNT) {
+                        return {
+                            type: SYNTAX.MemberExpression,
+                            object: node.object,
+                            property: {
+                                type: SYNTAX.Identifier,
+                                name: stringVariables[str].name
+                            },
+                            computed: true
+                        };
+                    }
+                }
+            }
+        }
+    });
+
+    // Add variables in the top
+    for (var str in stringVariables) {
+        // Used more than once
+        if (stringVariables[str].count > STR_MIN_COUNT) {
+            ast.body.unshift(createDeclaration([
+                createDeclarator(stringVariables[str].name, str)
+            ]));
+        }
+    }
+
+    return escodegen.generate(
+        ast,
+        {
+            format: {escapeless: true},
+            comment: true
+        }
+    );
+}
+
+exports = module.exports = mangleString;