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Code Issues Releases Wiki Activity

Refactor filter compilation to allow SQL engine to optimise queries

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This commit is contained in:
Jeremy Ruston 2023-11-07 21:08:58 +00:00
parent d7f0c5cb6b
commit 6997c61bc1
1 changed files with 39 additions and 25 deletions
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58
core/modules/filters.js
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@ -225,6 +225,7 @@ source: an iterator function for the source tiddlers, called source(iterator), w
widget: an optional widget node for retrieving the current tiddler etc.
*/
exports.compileFilter = function(filterString) {
var self = this;
// Set up the filter function cache
if(!this.filterCache) {
this.filterCache = Object.create(null);
@ -244,10 +245,42 @@ exports.compileFilter = function(filterString) {
return [$tw.language.getString("Error/Filter") + ": " + e];
};
}
// Get the filter function
var fnFilter = this.optimiseFilter && this.optimiseFilter(filterString);
if(!fnFilter) {
fnFilter = this.compileFilterToJavaScript(filterParseTree);
}
// Add recursion detection
var fnGuardedFilter = function guardedFilterFunction(source,widget) {
var results;
self.filterRecursionCount = (self.filterRecursionCount || 0) + 1;
if(self.filterRecursionCount < MAX_FILTER_DEPTH) {
results = fnFilter(source,widget);
} else {
results = ["/**-- Excessive filter recursion --**/"];
}
self.filterRecursionCount = self.filterRecursionCount - 1;
return results;
}
// Add performance measurement
var fnMeasured = $tw.perf.measure("filter: " + filterString,fnGuardedFilter);
// Cache the final filter function
if(this.filterCacheCount >= 2000) {
// To prevent memory leak, we maintain an upper limit for cache size.
// Reset if exceeded. This should give us 95% of the benefit
// that no cache limit would give us.
this.filterCache = Object.create(null);
this.filterCacheCount = 0;
}
this.filterCache[filterString] = fnMeasured;
this.filterCacheCount++;
return fnMeasured;
};
exports.compileFilterToJavaScript = function(filterParseTree) {
var operationFunctions = [];
// Get the hashmap of filter operator functions
var filterOperators = this.getFilterOperators();
// Assemble array of functions, one for each operation
var operationFunctions = [];
// Step through the operations
var self = this;
$tw.utils.each(filterParseTree,function(operation) {
@ -338,7 +371,7 @@ exports.compileFilter = function(filterString) {
})());
});
// Make the filter function
var fnFilter = function filterFunction(source,widget) {
return function filterFunction(source,widget) {
if(!source) {
source = self.each;
} else if(typeof source === "object") { // Array or hashmap
@ -348,30 +381,11 @@ exports.compileFilter = function(filterString) {
widget = $tw.rootWidget;
}
var results = new $tw.utils.LinkedList();
self.filterRecursionCount = (self.filterRecursionCount || 0) + 1;
if(self.filterRecursionCount < MAX_FILTER_DEPTH) {
$tw.utils.each(operationFunctions,function(operationFunction) {
operationFunction(results,source,widget);
});
} else {
results.push("/**-- Excessive filter recursion --**/");
}
self.filterRecursionCount = self.filterRecursionCount - 1;
return results.toArray();
};
// Return a function that applies the operations to a source iterator of tiddler titles
var fnMeasured = $tw.perf.measure("filter: " + filterString,fnFilter);
// Cache the measured filter function
if(this.filterCacheCount >= 2000) {
// To prevent memory leak, we maintain an upper limit for cache size.
// Reset if exceeded. This should give us 95% of the benefit
// that no cache limit would give us.
this.filterCache = Object.create(null);
this.filterCacheCount = 0;
}
this.filterCache[filterString] = fnMeasured;
this.filterCacheCount++;
return fnMeasured;
};
})();