Files
genieacs/lib/common/expression.ts
T
Zaid Abdulla bc2d258f9c Refactor bool exp synthesizer
It's now more intelligent about generating IS NULL clauses. For example,
instead of 'LOWER(param) IS NULL' it now generates 'param IS NULL'.
2021-09-16 13:27:37 -07:00

401 lines
12 KiB
TypeScript

/**
* Copyright 2013-2019 GenieACS Inc.
*
* This file is part of GenieACS.
*
* GenieACS is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* GenieACS is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with GenieACS. If not, see <http://www.gnu.org/licenses/>.
*/
import { map, mapAsync, parseLikePattern } from "./expression-parser";
import { Expression } from "../types";
const isArray = Array.isArray;
const regExpCache = new WeakMap<any, RegExp>();
const REDUCE_SKIP = {};
function reduce(exp, callback): Expression {
let loop = true;
while (loop) {
loop = false;
for (let i = 2; i < exp.length; ++i) {
const res = callback(exp[i - 1], exp[i], i - 2);
if (res !== REDUCE_SKIP) {
loop = true;
exp = exp.slice();
exp.splice(i - 1, 2, res);
}
}
}
if (exp.length === 2) return exp[1];
return exp;
}
export function likePatternToRegExp(pat: string, esc = "", flags = ""): RegExp {
const convChars = {
"-": "\\-",
"/": "\\/",
"\\": "\\/",
"^": "\\^",
$: "\\$",
"*": "\\*",
"+": "\\+",
"?": "\\?",
".": "\\.",
"(": "\\(",
")": "\\)",
"|": "\\|",
"[": "\\[",
"]": "\\]",
"{": "\\{",
"}": "\\}",
"\\%": ".*",
"\\_": ".",
};
let chars = parseLikePattern(pat, esc);
if (!chars.length) return new RegExp("^$", flags);
chars = chars.map((c) => convChars[c] || c);
chars[0] = chars[0] === ".*" ? "" : "^" + chars[0];
const l = chars.length - 1;
chars[l] = [".*", ""].includes(chars[l]) ? "" : chars[l] + "$";
return new RegExp(chars.join(""), flags);
}
function compare(
a: boolean | number | string,
b: boolean | number | string
): number {
if (typeof a === "boolean") a = +a;
if (typeof b === "boolean") b = +b;
if (typeof a !== typeof b) return typeof a === "string" ? 1 : -1;
return a > b ? 1 : a < b ? -1 : 0;
}
function toNumber(a: boolean | number | string): number {
switch (typeof a) {
case "number":
return a;
case "boolean":
return +a;
case "string":
return parseFloat(a) || 0;
}
}
function toString(a: boolean | number | string): string {
switch (typeof a) {
case "string":
return a;
case "number":
return a.toString();
case "boolean":
return (+a).toString();
}
}
export function evaluateCallback(exp: Expression): Expression {
if (!Array.isArray(exp)) return exp;
if (exp[0] === "CASE") {
for (let i = 1; i < exp.length; i += 2) {
if (Array.isArray(exp[i])) return exp;
if (exp[i]) return exp[i + 1];
}
return null;
} else if (exp[0] === "FUNC") {
if (exp[1] === "COALESCE") {
const args: Expression[] = [];
for (let i = 2; i < exp.length; ++i) {
const e = exp[i];
if (e == null) continue;
args.push(e);
if (!Array.isArray(e)) break;
}
if (!args.length) return null;
if (args.length === 1) return args[0];
return ["FUNC", "COALESCE", ...args];
} else if (exp[1] === "UPPER") {
if (exp[2] == null) return null;
if (!isArray(exp[2])) return toString(exp[2]).toUpperCase();
} else if (exp[1] === "LOWER") {
if (exp[2] == null) return null;
if (!isArray(exp[2])) return toString(exp[2]).toLowerCase();
} else if (exp[1] === "ROUND") {
const n = exp[2];
const p = exp.length > 3 ? exp[3] : 0;
if (n == null || p == null) return null;
if (!isArray(n) && !isArray(p)) {
const d = 10 ** p;
const m = n * d * (1 + Number.EPSILON);
return Math.round(m) / d;
}
}
} else if (exp[0] === "PARAM") {
if (exp[1] == null) return null;
} else if (exp[0] === "AND") {
for (let i = 1; i < exp.length; ++i)
if (!Array.isArray(exp[i]) && exp[i] != null && !exp[i]) return false;
const args: Expression[] = [];
for (let i = 1; i < exp.length; ++i) {
const ee = exp[i];
if (ee == null) return null;
if (Array.isArray(ee)) {
if (ee[0] === "AND") args.push(...ee.slice(1));
else args.push(ee);
}
}
if (!args.length) return true;
if (args.length === 1) args.push(true);
return ["AND", ...args];
} else if (exp[0] === "OR") {
const args: Expression[] = [];
for (let i = 1; i < exp.length; ++i) {
const ee = exp[i];
if (Array.isArray(ee)) {
if (ee[0] === "OR") args.push(...ee.slice(1));
else args.push(ee);
} else if (ee) {
return true;
}
}
if (!args.length) return exp.some((ee) => ee == null) ? null : false;
if (args.length === 1) args.push(false);
return ["OR", ...args];
} else if (exp[0] === "NOT") {
if (exp[1] == null) return null;
if (!isArray(exp[1])) return !exp[1];
else if (exp[1][0] === "NOT") return exp[1][1];
} else if (exp[0] === "IS NULL") {
if (isArray(exp[1])) return exp;
else if (exp[1] == null) return true;
else return false;
} else if (exp[0] === "IS NOT NULL") {
if (isArray(exp[1])) return exp;
else if (exp[1] != null) return true;
else return false;
} else if (exp[0] === "LIKE") {
if (isArray(exp[1]) || isArray(exp[2]) || isArray(exp[3])) return exp;
else if (
exp[1] == null ||
exp[2] == null ||
((exp as any[]).length >= 4 && exp[3] == null)
)
return null;
let r = regExpCache.get(exp as any[]);
if (!r) {
r = likePatternToRegExp(exp[2], exp[3]);
regExpCache.set(exp as any[], r);
}
return r.test(exp[1]);
} else if (exp[0] === "NOT LIKE") {
if (isArray(exp[1]) || isArray(exp[2]) || isArray(exp[3])) return exp;
else if (
exp[1] == null ||
exp[2] == null ||
((exp as any[]).length >= 4 && exp[3] == null)
)
return null;
let r = regExpCache.get(exp as any[]);
if (!r) {
r = likePatternToRegExp(exp[2], exp[3]);
regExpCache.set(exp as any[], r);
}
return !r.test(exp[1]);
} else if (exp[0] === "=") {
if (exp[1] == null || exp[2] == null) return null;
if (isArray(exp[1]) || isArray(exp[2])) return exp;
return compare(exp[1], exp[2]) === 0;
} else if (exp[0] === "<>") {
if (exp[1] == null || exp[2] == null) return null;
if (isArray(exp[1]) || isArray(exp[2])) return exp;
return compare(exp[1], exp[2]) !== 0;
} else if (exp[0] === ">") {
if (exp[1] == null || exp[2] == null) return null;
if (isArray(exp[1]) || isArray(exp[2])) return exp;
return compare(exp[1], exp[2]) > 0;
} else if (exp[0] === ">=") {
if (exp[1] == null || exp[2] == null) return null;
if (isArray(exp[1]) || isArray(exp[2])) return exp;
return compare(exp[1], exp[2]) >= 0;
} else if (exp[0] === "<") {
if (exp[1] == null || exp[2] == null) return null;
if (isArray(exp[1]) || isArray(exp[2])) return exp;
return compare(exp[1], exp[2]) < 0;
} else if (exp[0] === "<=") {
if (exp[1] == null || exp[2] == null) return null;
if (isArray(exp[1]) || isArray(exp[2])) return exp;
return compare(exp[1], exp[2]) <= 0;
} else if (exp[0] === "*") {
return reduce(exp, (a, b) => {
if (a == null || b == null) return null;
if (!isArray(a) && !isArray(b)) return toNumber(a) * toNumber(b);
return REDUCE_SKIP;
});
} else if (exp[0] === "/") {
return reduce(exp, (a, b, i) => {
if (a == null || b == null) return null;
if (!isArray(a) && !isArray(b))
return i === 0 ? toNumber(a) / toNumber(b) : toNumber(a) * toNumber(b);
return REDUCE_SKIP;
});
} else if (exp[0] === "+") {
return reduce(exp, (a, b) => {
if (a == null || b == null) return null;
if (!isArray(a) && !isArray(b)) return toNumber(a) + toNumber(b);
return REDUCE_SKIP;
});
} else if (exp[0] === "-") {
return reduce(exp, (a, b, i) => {
if (a == null || b == null) return null;
if (!isArray(a) && !isArray(b))
return i === 0 ? toNumber(a) - toNumber(b) : toNumber(a) + toNumber(b);
return REDUCE_SKIP;
});
} else if (exp[0] === "||") {
return reduce(exp, (a, b) => {
if (a == null || b == null) return null;
if (!isArray(a) && !isArray(b)) return toString(a) + toString(b);
return REDUCE_SKIP;
});
}
return exp;
}
export function evaluate(
exp: Expression,
obj: Record<string, unknown> | ((e: string) => Expression),
now: number,
cb?: (e: Expression) => Expression
): string | number | boolean | null;
export function evaluate(
exp: Expression,
obj?: Record<string, unknown> | ((e: string) => Expression),
now?: number,
cb?: (e: Expression) => Expression
): Expression;
export function evaluate(
exp: Expression,
obj?: Record<string, unknown> | ((e: string) => Expression),
now?: number,
cb?: (e: Expression) => Expression
): Expression {
return map(exp, (e) => {
if (cb) e = cb(e);
if (!isArray(e)) return e;
if (e[0] === "FUNC" && e[1] === "NOW") {
if (now) return now;
} else if (e[0] === "PARAM") {
if (e[1] == null) return null;
if (obj && !isArray(e[1])) {
let v;
if (typeof obj === "function") v = obj(e[1]);
else v = obj[e[1]];
if (v == null) return null;
if (typeof v === "object") v = v.value ? v.value[0] : null;
return v;
}
}
return evaluateCallback(e);
});
}
export async function evaluateAsync(
exp: Expression,
obj: Record<string, unknown>,
now: number,
cb?: (e: Expression) => Promise<Expression>
): Promise<string | number | boolean | null>;
export async function evaluateAsync(
exp: Expression,
obj?: Record<string, unknown>,
now?: number,
cb?: (e: Expression) => Promise<Expression>
): Promise<Expression>;
export async function evaluateAsync(
exp: Expression,
obj?: Record<string, unknown>,
now?: number,
cb?: (e: Expression) => Promise<Expression>
): Promise<Expression> {
return mapAsync(exp, async (e) => {
if (cb) e = await cb(e);
if (!isArray(e)) return e;
if (e[0] === "FUNC") {
if (e[1] === "NOW") if (now) return now;
} else if (e[0] === "PARAM") {
if (e[1] == null) return null;
if (obj && !isArray(e[1])) {
let v = obj[e[1]];
if (v == null) return null;
if (typeof v === "object") v = v["value"] ? v["value"][0] : null;
return v as Expression;
}
}
return evaluateCallback(e);
});
}
export function and(exp1: Expression, exp2: Expression): Expression {
if (exp1 != null && !exp1) return false;
if (exp2 != null && !exp2) return false;
if (!Array.isArray(exp1) && !Array.isArray(exp2)) {
if (exp1 == null || exp2 == null) return null;
return true;
}
if (!Array.isArray(exp2) && exp1[0] === "AND") return exp1;
if (!Array.isArray(exp1) && exp2[0] === "AND") return exp2;
const res: Expression = ["AND"];
if (Array.isArray(exp1) && exp1[0] === "AND") res.push(...exp1.slice(1));
else res.push(exp1);
if (Array.isArray(exp2) && exp2[0] === "AND") res.push(...exp2.slice(1));
else res.push(exp2);
return res;
}
export function or(exp1: Expression, exp2: Expression): Expression {
if (!Array.isArray(exp1) && exp1) return true;
if (!Array.isArray(exp2) && exp2) return true;
if (!Array.isArray(exp1) && !Array.isArray(exp2)) {
if (exp1 == null || exp2 == null) return null;
return false;
}
if (!Array.isArray(exp2) && exp1[0] === "OR") return exp1;
if (!Array.isArray(exp1) && exp2[0] === "OR") return exp2;
const res: Expression = ["OR"];
if (Array.isArray(exp1) && exp1[0] === "OR") res.push(...exp1.slice(1));
else res.push(exp1);
if (Array.isArray(exp2) && exp2[0] === "OR") res.push(...exp2.slice(1));
else res.push(exp2);
return res;
}
export function extractParams(exp: Expression): Expression[] {
const params = new Set<Expression>();
map(exp, (e) => {
if (isArray(e) && e[0] === "PARAM") params.add(e[1]);
return e;
});
return Array.from(params);
}