From a4bcd4451cefef10364bdd46677403e354177a86 Mon Sep 17 00:00:00 2001
From: CalDescent <caldescent@protonmail.com>
Date: Sat, 30 Apr 2022 12:07:47 +0100
Subject: [PATCH] Added "tail" parameter to GET /admin/logs to allow returning
 the last X (limit) lines.

This should make it easy to display core logs in the UI.
---
 .../java/org/qortal/api/resource/AdminResource.java   | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/main/java/org/qortal/api/resource/AdminResource.java b/src/main/java/org/qortal/api/resource/AdminResource.java
index 277b5f00..b14d774f 100644
--- a/src/main/java/org/qortal/api/resource/AdminResource.java
+++ b/src/main/java/org/qortal/api/resource/AdminResource.java
@@ -381,6 +381,10 @@ public class AdminResource {
 			) @QueryParam("limit") Integer limit, @Parameter(
 				ref = "offset"
 			) @QueryParam("offset") Integer offset, @Parameter(
+				name = "tail",
+				description = "Fetch most recent log lines",
+				schema = @Schema(type = "boolean")
+			) @QueryParam("tail") Boolean tail, @Parameter(
 				ref = "reverse"
 			) @QueryParam("reverse") Boolean reverse) {
 		LoggerContext loggerContext = (LoggerContext) LogManager.getContext();
@@ -396,6 +400,13 @@ public class AdminResource {
 			if (reverse != null && reverse)
 				logLines = Lists.reverse(logLines);
 
+			// Tail mode - return the last X lines (where X = limit)
+			if (tail != null && tail) {
+				if (limit != null && limit > 0) {
+					offset = logLines.size() - limit;
+				}
+			}
+
 			// offset out of bounds?
 			if (offset != null && (offset < 0 || offset >= logLines.size()))
 				return "";