HDFS-17791: Fix libhdfs client that needlessly outputs full stack trace for common "file not found" errors

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfs/exception.c

@@ -189,12 +189,25 @@ int printExceptionAndFreeV(JNIEnv *env, jthrowable exc, int noPrintFlags,
  if (!rootCause) {
  fprintf(stderr, "(unable to get root cause for %s)\n", className);
  } else {
- fprintf(stderr, "%s", rootCause);
+ // Trim overly long rootCause message after new-line.
+ const char *newlnIndex = strchr(rootCause, '\n');
+ int displayLen = 80;
+ if (newlnIndex != NULL) {
+ int newLen = (int) (newlnIndex - rootCause);
+ if (newLen > 10 && newLen < 200) {
+ // Keep message a reasonable length.
+ displayLen = newLen;
+ }
+ }
+ fprintf(stderr, "%.*s\n", displayLen, rootCause);
  }
- if (!stackTrace) {
- fprintf(stderr, "(unable to get stack trace for %s)\n", className);
- } else {
- fprintf(stderr, "%s", stackTrace);
+ if (!(noPrintFlags & NOSTACK_FILE_NOT_FOUND)) {
+ // Do not print stack for file not found
+ if (!stackTrace) {
+ fprintf(stderr, "(unable to get stack trace for %s)\n", className);
+ } else {
+ fprintf(stderr, "%s", stackTrace);
+ }
  }
  }
 

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfs/exception.h

@@ -65,6 +65,7 @@
  */
 #define PRINT_EXC_ALL 0x00
 #define NOPRINT_EXC_FILE_NOT_FOUND 0x01
+#define NOSTACK_FILE_NOT_FOUND 0x100
 #define NOPRINT_EXC_ACCESS_CONTROL 0x02
 #define NOPRINT_EXC_UNRESOLVED_LINK 0x04
 #define NOPRINT_EXC_PARENT_NOT_DIRECTORY 0x08

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfs/hdfs.c

@@ -1247,7 +1247,7 @@ static hdfsFile hdfsOpenFileImpl(hdfsFS fs, const char *path, int flags,
  jReplication, jBlockSize);
  }
  if (jthr) {
- ret = printExceptionAndFree(env, jthr, PRINT_EXC_ALL,
+ ret = printExceptionAndFree(env, jthr, NOSTACK_FILE_NOT_FOUND,
  "hdfsOpenFile(%s): FileSystem#%s(%s)", path, method, signature);
  goto done;
  }