feat: read cache settings from env var (#31)

Description
---
Read cache related settings on the start from env var (with some default
values).

Motivation and Context
---

How Has This Been Tested?
---
See the cache settings, try to change the env var and rerun to see the
effect.

What process can a PR reviewer use to test or verify this change?
---

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Breaking Changes
---

- [x] None
- [ ] Requires data directory on base node to be deleted
- [ ] Requires hard fork
- [ ] Other - Please specify

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cacheSettings.js

@@ -0,0 +1,18 @@
+var cacheSettings = {
+  index:
+    process.env.TARI_EXPLORER_INDEX_CACHE_SETTINGS ||
+    "public, max-age=120, s-maxage=60, stale-while-revalidate=30",
+  mempool:
+    process.env.TARI_EXPLORER_MEMPOOL_CACHE_SETTINGS ||
+    "public, max-age=15, s-maxage=15, stale-while-revalidate=15",
+  oldBlocks:
+    process.env.TARI_EXPLORER_OLD_BLOCKS_CACHE_SETTINGS ||
+    "public, max-age=604800, s-maxage=604800, stale-while-revalidate=604800",
+  newBlocks:
+    process.env.TARI_EXPLORER_NEW_BLOCKS_CACHE_SETTINGS ||
+    "public, max-age=120, s-maxage=60, stale-while-revalidate=30",
+  oldBlockDeltaTip:
+    process.env.TARI_EXPLORER_OLD_BLOCK_DELTA_TIP || 30 * 24 * 7,
+};
+
+module.exports = cacheSettings;

routes/assets.js

@@ -35,7 +35,6 @@ router.get("/:asset_public_key", async function (req, res) {
     let tokens = await baseNodeClient.getTokens({
       asset_public_key: Buffer.from(asset_public_key, "hex"),
     });
-    console.log(tokens);
 
     if (!tokens || tokens.length === 0) {
       res.status(404);

routes/blocks.js

@@ -24,6 +24,7 @@ var { createClient } = require("../baseNodeClient");
 
 var express = require("express");
 const cache = require("../cache");
+const cacheSettings = require("../cacheSettings");
 var router = express.Router();
 
 function fromHexString(hexString) {
@@ -35,7 +36,6 @@ function fromHexString(hexString) {
 }
 
 router.get("/:height_or_hash", async function (req, res) {
-  res.setHeader("Cache-Control", "public, max-age=120, immutable");
   try {
     let client = createClient();
     let height_or_hash = req.params.height_or_hash;
@@ -213,6 +213,12 @@ router.get("/:height_or_hash", async function (req, res) {
     let nextLink = `/blocks/${nextHeight}`;
     if (height === tipHeight) nextLink = null;
 
+    if (height + cacheSettings.oldBlockDeltaTip <= tipHeight) {
+      res.setHeader("Cache-Control", cacheSettings.oldBlocks);
+    } else {
+      res.setHeader("Cache-Control", cacheSettings.newBlocks);
+    }
+
     let json = {
       title: `Block at height: ${block[0].block.header.height}`,
       header: block[0].block.header,

routes/index.js

@@ -4,10 +4,12 @@
 var { createClient } = require("../baseNodeClient");
 
 var express = require("express");
+const cacheSettings = require("../cacheSettings");
 var router = express.Router();
 
 /* GET home page. */
 router.get("/", async function (req, res) {
+  res.setHeader("Cache-Control", cacheSettings.index);
   try {
     let client = createClient();
     let from = parseInt(req.query.from || 0);
@@ -27,8 +29,6 @@ router.get("/", async function (req, res) {
     let monero = [0, 0, 0, 0];
     let sha = [0, 0, 0, 0];
 
-    // console.log(last100Headers)
-
     for (let i = 0; i < last100Headers.length - 1; i++) {
       let arr = last100Headers[i].pow.pow_algo === "0" ? monero : sha;
       if (i < 10) {
@@ -53,7 +53,6 @@ router.get("/", async function (req, res) {
       sha100: sha[3],
     };
 
-    // console.log(algoSplit)
     // Get one more header than requested so we can work out the difference in MMR_size
     let headersResp = await client.listHeaders({
       from_height: from,
@@ -78,7 +77,6 @@ router.get("/", async function (req, res) {
       headers.splice(headers.length - 1, 1);
     }
 
-    // console.log(headers);
     let firstHeight = parseInt(headers[0].height || "0");
 
     // --  mempool
@@ -104,7 +102,6 @@ router.get("/", async function (req, res) {
       height: tipHeight,
     });
 
-    // console.log(mempool);
     for (let i = 0; i < mempool.length; i++) {
       let sum = 0;
       for (let j = 0; j < mempool[i].transaction.body.kernels.length; j++) {

routes/mempool.js

@@ -3,15 +3,15 @@
 
 var express = require("express");
 const { createClient } = require("../baseNodeClient");
+const cacheSettings = require("../cacheSettings");
 var router = express.Router();
 
 /* GET mempool page. */
 router.get("/:excessSigs", async function (req, res) {
-  res.setHeader("Cache-Control", "public, max-age=0, must-revalidate");
+  res.setHeader("Cache-Control", cacheSettings.mempool);
   try {
     let client = createClient();
     let txId = req.params.excessSigs.split("+");
-    console.log(txId);
     let mempool = await client.getMempoolTransactions({});
     let tx = null;
     for (let i = 0; i < mempool.length; i++) {
@@ -42,8 +42,6 @@ router.get("/:excessSigs", async function (req, res) {
       }
       return;
     }
-    console.log(tx);
-    console.log("===============");
     let json = { tx };
     if (req.query.json !== undefined) {
       res.json(json);

routes/search_commitments.js

@@ -23,10 +23,11 @@
 var { createClient } = require("../baseNodeClient");
 
 var express = require("express");
+const cacheSettings = require("../cacheSettings");
 var router = express.Router();
 
 router.get("/", async function (req, res) {
-  res.setHeader("Cache-Control", "public, max-age=120, immutable");
+  res.setHeader("Cache-Control", cacheSettings.newBlocks);
   let client = createClient();
   let commitments = (
     req.query.comm ||

routes/search_kernels.js

@@ -23,10 +23,11 @@
 var { createClient } = require("../baseNodeClient");
 
 var express = require("express");
+const cacheSettings = require("../cacheSettings");
 var router = express.Router();
 
 router.get("/", async function (req, res) {
-  res.setHeader("Cache-Control", "public, max-age=120, immutable");
+  res.setHeader("Cache-Control", cacheSettings.newBlocks);
   let client = createClient();
   let nonces = (req.query.nonces || "").split(",");
   let signatures = (req.query.signatures || "").split(",");