Add .properties file with current library descriptor format version. Log warning if format has been updated

Author: nikitinas

libraries/.properties

@@ -1 +1 @@
-formatVersion=1.0
+formatVersion=1

src/main/kotlin/org/jetbrains/kotlin/jupyter/config.kt

@@ -2,9 +2,11 @@ package org.jetbrains.kotlin.jupyter
 
 import com.beust.klaxon.JsonObject
 import com.beust.klaxon.Parser
+import khttp.responses.Response
 import kotlinx.coroutines.Deferred
 import kotlinx.coroutines.GlobalScope
 import kotlinx.coroutines.async
+import org.jetbrains.kotlin.konan.parseKonanVersion
 import org.json.JSONObject
 import org.slf4j.LoggerFactory
 import java.io.File
@@ -25,6 +27,7 @@ val GitHubBranchName = "remote_config"
 val GitHubApiPrefix = "https://$GitHubApiHost/repos/$GitHubRepoOwner/$GitHubRepoName"
 
 val LibraryDescriptorExt = "json"
+val LibraryPropertiesFile = ".properties"
 
 internal val log by lazy { LoggerFactory.getLogger("ikotlin") }
 
@@ -48,7 +51,7 @@ data class KernelConfig(
 
 val protocolVersion = "5.3"
 
-val libraryDescriptorFormatVersion = "1.0"
+val libraryDescriptorFormatVersion = 1
 
 data class TypeRenderer(val className: String, val displayCode: String?, val resultCode: String?)
 
@@ -99,7 +102,7 @@ fun getLatestCommitToLibraries(sinceTimestamp: String?): Pair<String, String>? =
             if (sinceTimestamp != null)
                 url += "&since=$sinceTimestamp"
             log.info("Checking for new commits to library descriptors at $url")
-            val arr = khttp.get(url).jsonArray
+            val arr = getHttp(url).jsonArray
             if (arr.length() == 0) {
                 if (sinceTimestamp != null)
                     getLatestCommitToLibraries(null)
@@ -115,6 +118,25 @@ fun getLatestCommitToLibraries(sinceTimestamp: String?): Pair<String, String>? =
             }
         }
 
+fun getHttp(url: String): Response {
+    val response = khttp.get(url)
+    if (response.statusCode != 200)
+        throw Exception("Http request failed. Url = $url. Response = $response")
+    return response
+}
+
+fun getLibraryDescriptorVersion(commitSha: String) =
+        log.catchAll {
+            val url = "$GitHubApiPrefix/contents/$LibrariesDir/$LibraryPropertiesFile?ref=$commitSha"
+            log.info("Checking current library descriptor format version from $url")
+            val response = getHttp(url)
+            val downloadUrl = (response as JSONObject)["download_url"].toString()
+            val downloadResult = getHttp(downloadUrl)
+            val result = downloadResult.text.parseIniConfig()["formatVersion"]!!.toInt()
+            log.info("Current library descriptor format version: $result")
+            result
+        }
+
 /***
  * Downloads library descriptors from GitHub to local cache if new commits in `libraries` directory were detected
  */
@@ -126,7 +148,7 @@ fun downloadNewLibraryDescriptors() {
     val footprintFilePath = Paths.get(LocalSettingsPath, LocalCacheDir, CachedLibrariesFootprintFile).toString()
     log.info("Reading commit info for which library descriptors were cached: '$footprintFilePath'")
     val footprintFile = File(footprintFilePath)
-    val footprint = footprintFile.readIniConfig()
+    val footprint = footprintFile.tryReadIniConfig()
     val timestampRegex = """\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}Z""".toRegex()
     val syncedCommitTimestamp = footprint?.get("timestamp")?.validOrNull { timestampRegex.matches(it) }
     val syncedCommitSha = footprint?.get("sha")
@@ -138,26 +160,33 @@ fun downloadNewLibraryDescriptors() {
         return
     }
 
+    // Download library descriptor version
+
+    val descriptorVersion = getLibraryDescriptorVersion(latestCommitSha) ?: return
+    if (descriptorVersion != libraryDescriptorFormatVersion) {
+        if (descriptorVersion < libraryDescriptorFormatVersion)
+            log.error("Incorrect library descriptor version in GitHub repository: $descriptorVersion")
+        else
+            log.warn("Couldn't download new library descriptors from GitHub repository because their format was updated. Please, update kotlin jupyter kernel to the latest version")
+        return
+    }
+
     // Download library descriptors
 
     log.info("New commits to library descriptors were detected. Downloading library descriptors for commit $latestCommitSha")
 
     val libraries = log.catchAll {
         val url = "$GitHubApiPrefix/contents/$LibrariesDir?ref=$latestCommitSha"
         log.info("Requesting the list of library descriptors at $url")
-        val response = khttp.get(url)
-        if (response.statusCode != 200)
-            throw Exception("Failed to get GitHub contents for '$LibrariesDir' from $url. Response = $response")
+        val response = getHttp(url)
 
         response.jsonArray.mapNotNull {
             val o = it as JSONObject
             val filename = o["name"] as String
             if ("""[\w-]+.$LibraryDescriptorExt""".toRegex().matches(filename)) {
                 val libUrl = o["download_url"].toString()
                 log.info("Downloading '$filename' from $libUrl")
-                val res = khttp.get(libUrl)
-                if (res.statusCode != 200)
-                    throw Exception("Failed to download '$filename' from $libUrl. Response = $res")
+                val res = getHttp(libUrl)
                 val text = res.jsonObject.toString()
                 filename to text
             } else null

src/main/kotlin/org/jetbrains/kotlin/jupyter/util.kt

@@ -39,9 +39,12 @@ fun <T, R> Deferred<T>.asyncLet(selector: suspend (T) -> R): Deferred<R> = this.
 
 fun <T> Deferred<T>.awaitBlocking(): T = if (isCompleted) getCompleted() else runBlocking { await() }
 
-fun File.readIniConfig() =
+fun String.parseIniConfig() =
+        split("\n").map { it.split('=') }.filter { it.count() == 2 }.map { it[0] to it[1] }.toMap()
+
+fun File.tryReadIniConfig() =
         existsOrNull()?.let {
-            catchAll { it.readLines().map { it.split('=') }.filter { it.count() == 2 }.map { it[0] to it[1] }.toMap() }
+            catchAll { it.readText().parseIniConfig() }
         }
 
 fun readJson(path: String) =