FEAT: included delete-thru in the thru-cache module and storing content locally only when response code is 200 (OK)

related to: Oldes/Rebol-issues#2554

Author: Oldes

src/modules/thru-cache.reb

@@ -4,21 +4,23 @@ Rebol [
 	name:    thru-cache
 	type:    module
 	options: [delay]
-	version: 0.2.0
-	exports: [path-thru read-thru load-thru do-thru clear-thru list-thru exists-thru?]
+	version: 0.2.1
+	exports: [path-thru read-thru load-thru do-thru clear-thru list-thru exists-thru? delete-thru]
 	author:  @Oldes
 	file:    %thru-cache.reb
 	home:    https://src.rebol.tech/modules/thru-cache.reb
 ]
 
 ;; Initialize the directory for storing local files
 so: system/options
+so/log/thru-cache: 2
+
 unless select so 'thru-cache [
 	put so 'thru-cache join to-real-file any [
 		get-env "TEMP"
 		so/data
 	] %thru-cache/
-	sys/log/info 'REBOL ["Using thru-cache:" mold so/thru-cache]
+	sys/log/info 'THRU-CACHE ["Content directory:" mold so/thru-cache]
 ]
 
 path-thru: func [
@@ -28,7 +30,7 @@ path-thru: func [
 	/local hash file path
 ][
 	unless find so 'thru-cache [return none]
-	hash: checksum form url 'MD5 
+	hash: checksum mold url 'MD5 
 	file: head (remove back tail remove remove (form hash)) 
 	path: dirize append copy so/thru-cache copy/part file 2 
 	unless exists? path [make-dir/deep path] 
@@ -40,13 +42,14 @@ read-thru: func [
 	url [url!] "Remote file address" 
 	/update "Force a cache update"
 	/string "Try convert result to string"
-	/local path data
+	/local path data code
 ][
 	path: path-thru url 
 	either all [not update exists? path] [
 		data: read/binary path
 	][
 		data: read/binary/all url
+		code: any [all [block? data data/1] 200]
 		if all [
 			block?  data
 			object? data/2
@@ -57,9 +60,14 @@ read-thru: func [
 				data/3
 			]
 		]
-		try [
-			write/binary path data
-			log-thru-file path url
+		either code == 200 [
+			try [
+				write/binary path data
+				log-thru-file path url
+				sys/log/more 'THRU-CACHE ["Stored:" mold url]
+			]
+		][
+			sys/log/debug 'THRU-CACHE ["Response" code " Not stored:" mold url]
 		]
 	]
 	if string [try [data: to string! data]]
@@ -99,7 +107,7 @@ clear-thru: func [
 			if all [
 				exists? dir/:path
 				find/any/match url filter
-			][	print [as-green skip path 3 url] ]
+			][	print [as-green skip path 3 mold url] ]
 		]
 		exit
 	]
@@ -128,11 +136,22 @@ exists-thru?: func[
 	exists? any [all [file? url url] path-thru url]
 ]
 
+delete-thru: func[
+	"Deletes a local disk cache file"
+	url [url!] "Remote file address"
+	/local path
+][
+	if exists? path: path-thru url [
+		sys/log/more 'THRU-CACHE ["Removed:" mold url]
+		delete path
+	]
+]
+
 list-thru: func[
 	"Prints localy stored URLs"
 	/only filter [string!] "List only the files that match the filter"
 ][
-	sys/log/info 'REBOL ["Used thru-cache directory:" mold so/thru-cache]
+	sys/log/info 'THRU-CACHE ["Content directory:" mold so/thru-cache]
 	clear-thru/:only/test filter
 ]
 

src/tests/units/thru-cache-test.r3

@@ -21,6 +21,13 @@ if module? try [import 'thru-cache][
 		equal? str1 str2
 		equal? str1 read/string url
 	]]
+	
+	--test-- "read-thru status <> 200"
+	url: http://httpbin.org/status/400
+	--assert try [all [
+		binary? read-thru url ;; returned, but not stored!
+		not exists-thru? url
+	]]
 
 	--test-- "load-thru"
 	url: https://raw.githubusercontent.com/Oldes/Rebol3/master/src/tests/units/files/print-args.r3
@@ -29,6 +36,10 @@ if module? try [import 'thru-cache][
 		block? blk2: load url
 		equal? blk1 blk2
 	]]
+
+	--test-- "exists-thru?"
+	--assert 'file = exists-thru? url
+	--assert   none? exists-thru? http://not-exists
 
 	--test-- "do-thru"
 	--assert not error? try [do-thru url] ;; evaluates the previously downloaded and cached script
@@ -41,6 +52,14 @@ if module? try [import 'thru-cache][
 		clear-thru ;; removes everything
 		--assert none? exists? path-thru url
 
+	--test-- "delete-thru"
+	--assert all [
+		binary? read-thru url
+		'file = exists-thru? url
+		port? delete-thru url
+		not exists-thru? url
+	]
+
 ===end-group===
 ]