HDFS-2727. libhdfs should get the default block size from the server. Contributed by Colin Patrick McCabe

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1375383 13f79535-47bb-0310-9956-ffa450edef68

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -405,6 +405,9 @@ Branch-2 ( Unreleased changes )
     HDFS-3672. Expose disk-location information for blocks to enable better
     scheduling. (Andrew Wang via atm)
 
+    HDFS-2727. libhdfs should get the default block size from the server.
+    (Colin Patrick McCabe via eli)
+
   OPTIMIZATIONS
 
     HDFS-2982. Startup performance suffers when there are many edit log

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

@@ -279,12 +279,19 @@ done:
     return ret;
 }
 
+struct hdfsBuilderConfOpt {
+    struct hdfsBuilderConfOpt *next;
+    const char *key;
+    const char *val;
+};
+
 struct hdfsBuilder {
     int forceNewInstance;
     const char *nn;
     tPort port;
     const char *kerbTicketCachePath;
     const char *userName;
+    struct hdfsBuilderConfOpt *opts;
 };
 
 struct hdfsBuilder *hdfsNewBuilder(void)
@@ -297,8 +304,32 @@ struct hdfsBuilder *hdfsNewBuilder(void)
     return bld;
 }
 
+int hdfsBuilderConfSetStr(struct hdfsBuilder *bld, const char *key,
+                          const char *val)
+{
+    struct hdfsBuilderConfOpt *opt, *next;
+    
+    opt = calloc(1, sizeof(struct hdfsBuilderConfOpt));
+    if (!opt)
+        return -ENOMEM;
+    next = bld->opts;
+    bld->opts = opt;
+    opt->next = next;
+    opt->key = key;
+    opt->val = val;
+    return 0;
+}
+
 void hdfsFreeBuilder(struct hdfsBuilder *bld)
 {
+    struct hdfsBuilderConfOpt *cur, *next;
+
+    cur = bld->opts;
+    for (cur = bld->opts; cur; ) {
+        next = cur->next;
+        free(cur);
+        cur = next;
+    }
     free(bld);
 }
 
@@ -451,6 +482,7 @@ hdfsFS hdfsBuilderConnect(struct hdfsBuilder *bld)
     char *cURI = 0, buf[512];
     int ret;
     jobject jRet = NULL;
+    struct hdfsBuilderConfOpt *opt;
 
     //Get the JNIEnv* corresponding to current thread
     env = getJNIEnv();
@@ -466,6 +498,16 @@ hdfsFS hdfsBuilderConnect(struct hdfsBuilder *bld)
             "hdfsBuilderConnect(%s)", hdfsBuilderToStr(bld, buf, sizeof(buf)));
         goto done;
     }
+    // set configuration values
+    for (opt = bld->opts; opt; opt = opt->next) {
+        jthr = hadoopConfSetStr(env, jConfiguration, opt->key, opt->val);
+        if (jthr) {
+            ret = printExceptionAndFree(env, jthr, PRINT_EXC_ALL,
+                "hdfsBuilderConnect(%s): error setting conf '%s' to '%s'",
+                hdfsBuilderToStr(bld, buf, sizeof(buf)), opt->key, opt->val);
+            goto done;
+        }
+    }
  
     //Check what type of FileSystem the caller wants...
     if (bld->nn == NULL) {
@@ -596,7 +638,7 @@ done:
     destroyLocalReference(env, jURIString);
     destroyLocalReference(env, jUserString);
     free(cURI);
-    free(bld);
+    hdfsFreeBuilder(bld);
 
     if (ret) {
         errno = ret;
@@ -644,7 +686,29 @@ int hdfsDisconnect(hdfsFS fs)
     return 0;
 }
 
+/**
+ * Get the default block size of a FileSystem object.
+ *
+ * @param env       The Java env
+ * @param jFS       The FileSystem object
+ * @param jPath     The path to find the default blocksize at
+ * @param out       (out param) the default block size
+ *
+ * @return          NULL on success; or the exception
+ */
+static jthrowable getDefaultBlockSize(JNIEnv *env, jobject jFS,
+                                      jobject jPath, jlong *out)
+{
+    jthrowable jthr;
+    jvalue jVal;
 
+    jthr = invokeMethod(env, &jVal, INSTANCE, jFS, HADOOP_FS,
+                 "getDefaultBlockSize", JMETHOD1(JPARAM(HADOOP_PATH), "J"), jPath);
+    if (jthr)
+        return jthr;
+    *out = jVal.j;
+    return NULL;
+}
 
 hdfsFile hdfsOpenFile(hdfsFS fs, const char* path, int flags, 
                       int bufferSize, short replication, tSize blockSize)
@@ -665,7 +729,6 @@ hdfsFile hdfsOpenFile(hdfsFS fs, const char* path, int flags,
     }
 
     jstring jStrBufferSize = NULL, jStrReplication = NULL;
-    jstring jStrBlockSize = NULL;
     jobject jConfiguration = NULL, jPath = NULL, jFile = NULL;
     jobject jFS = (jobject)fs;
     jthrowable jthr;
@@ -724,7 +787,6 @@ hdfsFile hdfsOpenFile(hdfsFS fs, const char* path, int flags,
 
     jint jBufferSize = bufferSize;
     jshort jReplication = replication;
-    jlong jBlockSize = blockSize;
     jStrBufferSize = (*env)->NewStringUTF(env, "io.file.buffer.size"); 
     if (!jStrBufferSize) {
         ret = printPendingExceptionAndFree(env, PRINT_EXC_ALL, "OOM");
@@ -735,11 +797,6 @@ hdfsFile hdfsOpenFile(hdfsFS fs, const char* path, int flags,
         ret = printPendingExceptionAndFree(env, PRINT_EXC_ALL, "OOM");
         goto done;
     }
-    jStrBlockSize = (*env)->NewStringUTF(env, "dfs.block.size");
-    if (!jStrBlockSize) {
-        ret = printPendingExceptionAndFree(env, PRINT_EXC_ALL, "OOM");
-        goto done;
-    }
 
     if (!bufferSize) {
         jthr = invokeMethod(env, &jVal, INSTANCE, jConfiguration, 
@@ -768,20 +825,6 @@ hdfsFile hdfsOpenFile(hdfsFS fs, const char* path, int flags,
             }
             jReplication = jVal.i;
         }
-        
-        //blockSize
-        if (!blockSize) {
-            jthr = invokeMethod(env, &jVal, INSTANCE, jConfiguration, 
-                             HADOOP_CONF, "getLong", "(Ljava/lang/String;J)J",
-                             jStrBlockSize, (jlong)67108864);
-            if (jthr) {
-                ret  = printExceptionAndFree(env, jthr, PRINT_EXC_ALL,
-                    "hdfsOpenFile(%s): Configuration#getLong(dfs.block.size)",
-                    path);
-                goto done;
-            }
-            jBlockSize = jVal.j;
-        }
     }
  
     /* Create and return either the FSDataInputStream or
@@ -798,6 +841,15 @@ hdfsFile hdfsOpenFile(hdfsFS fs, const char* path, int flags,
     } else {
         // WRITE/CREATE
         jboolean jOverWrite = 1;
+        jlong jBlockSize = blockSize;
+
+        if (jBlockSize == 0) {
+            jthr = getDefaultBlockSize(env, jFS, jPath, &jBlockSize);
+            if (jthr) {
+                ret = EIO;
+                goto done;
+            }
+        }
         jthr = invokeMethod(env, &jVal, INSTANCE, jFS, HADOOP_FS,
                          method, signature, jPath, jOverWrite,
                          jBufferSize, jReplication, jBlockSize);
@@ -842,7 +894,6 @@ hdfsFile hdfsOpenFile(hdfsFS fs, const char* path, int flags,
 done:
     destroyLocalReference(env, jStrBufferSize);
     destroyLocalReference(env, jStrReplication);
-    destroyLocalReference(env, jStrBlockSize);
     destroyLocalReference(env, jConfiguration); 
     destroyLocalReference(env, jPath); 
     destroyLocalReference(env, jFile); 
@@ -2142,6 +2193,39 @@ tOffset hdfsGetDefaultBlockSize(hdfsFS fs)
 }
 
 
+tOffset hdfsGetDefaultBlockSizeAtPath(hdfsFS fs, const char *path)
+{
+    // JAVA EQUIVALENT:
+    //  fs.getDefaultBlockSize(path);
+
+    jthrowable jthr;
+    jobject jFS = (jobject)fs;
+    jobject jPath;
+    tOffset blockSize;
+    JNIEnv* env = getJNIEnv();
+
+    if (env == NULL) {
+        errno = EINTERNAL;
+        return -1;
+    }
+    jthr = constructNewObjectOfPath(env, path, &jPath);
+    if (jthr) {
+        errno = printExceptionAndFree(env, jthr, PRINT_EXC_ALL,
+            "hdfsGetDefaultBlockSize(path=%s): constructNewObjectOfPath",
+            path);
+        return -1;
+    }
+    jthr = getDefaultBlockSize(env, jFS, jPath, &blockSize);
+    (*env)->DeleteLocalRef(env, jPath);
+    if (jthr) {
+        errno = printExceptionAndFree(env, jthr, PRINT_EXC_ALL,
+            "hdfsGetDefaultBlockSize(path=%s): "
+            "FileSystem#getDefaultBlockSize", path);
+        return -1;
+    }
+    return blockSize;
+}
+
 
 tOffset hdfsGetCapacity(hdfsFS fs)
 {

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

@@ -216,6 +216,20 @@ extern  "C" {
      */
     void hdfsFreeBuilder(struct hdfsBuilder *bld);
 
+    /**
+     * Set a configuration string for an HdfsBuilder.
+     *
+     * @param key      The key to set.
+     * @param val      The value, or NULL to set no value.
+     *                 This will be shallow-copied.  You are responsible for
+     *                 ensuring that it remains valid until the builder is
+     *                 freed.
+     *
+     * @return         0 on success; nonzero error code otherwise.
+     */
+    int hdfsBuilderConfSetStr(struct hdfsBuilder *bld, const char *key,
+                              const char *val);
+
     /**
      * Get a configuration string.
      *
@@ -234,7 +248,7 @@ extern  "C" {
      *
      * @param key      The key to find
      * @param val      (out param) The value.  This will NOT be changed if the
-	 *                 key isn't found.
+     *                 key isn't found.
      *
      * @return         0 on success; nonzero error code otherwise.
      *                 Failure to find the key is not an error.
@@ -550,13 +564,29 @@ extern  "C" {
 
 
     /** 
-     * hdfsGetDefaultBlockSize - Get the optimum blocksize.
+     * hdfsGetDefaultBlockSize - Get the default blocksize.
-     * @param fs The configured filesystem handle.
+     *
-     * @return Returns the blocksize; -1 on error. 
+     * @param fs            The configured filesystem handle.
+     * @deprecated          Use hdfsGetDefaultBlockSizeAtPath instead.
+     *
+     * @return              Returns the default blocksize, or -1 on error.
      */
     tOffset hdfsGetDefaultBlockSize(hdfsFS fs);
 
 
+    /** 
+     * hdfsGetDefaultBlockSizeAtPath - Get the default blocksize at the
+     * filesystem indicated by a given path.
+     *
+     * @param fs            The configured filesystem handle.
+     * @param path          The given path will be used to locate the actual
+     *                      filesystem.  The full path does not have to exist.
+     *
+     * @return              Returns the default blocksize, or -1 on error.
+     */
+    tOffset hdfsGetDefaultBlockSizeAtPath(hdfsFS fs, const char *path);
+
+
     /** 
      * hdfsGetCapacity - Return the raw capacity of the filesystem.  
      * @param fs The configured filesystem handle.

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

@@ -21,14 +21,20 @@
 #include "native_mini_dfs.h"
 
 #include <errno.h>
+#include <inttypes.h>
 #include <semaphore.h>
 #include <pthread.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
+#define TO_STR_HELPER(X) #X
+#define TO_STR(X) TO_STR_HELPER(X)
+
 #define TLH_MAX_THREADS 100
 
+#define TLH_DEFAULT_BLOCK_SIZE 134217728
+
 static sem_t tlhSem;
 
 static struct NativeMiniDfsCluster* tlhCluster;
@@ -46,6 +52,7 @@ static int hdfsSingleNameNodeConnect(struct NativeMiniDfsCluster *cl, hdfsFS *fs
 {
     int ret, port;
     hdfsFS hdfs;
+    struct hdfsBuilder *bld;
     
     port = nmdGetNameNodePort(cl);
     if (port < 0) {
@@ -53,7 +60,16 @@ static int hdfsSingleNameNodeConnect(struct NativeMiniDfsCluster *cl, hdfsFS *fs
                 "returned error %d\n", port);
         return port;
     }
-    hdfs = hdfsConnectNewInstance("localhost", port);
+    bld = hdfsNewBuilder();
+    if (!bld)
+        return -ENOMEM;
+    hdfsBuilderSetNameNode(bld, "localhost");
+    hdfsBuilderSetNameNodePort(bld, port);
+    hdfsBuilderConfSetStr(bld, "dfs.block.size",
+                          TO_STR(TLH_DEFAULT_BLOCK_SIZE));
+    hdfsBuilderConfSetStr(bld, "dfs.blocksize",
+                          TO_STR(TLH_DEFAULT_BLOCK_SIZE));
+    hdfs = hdfsBuilderConnect(bld);
     if (!hdfs) {
         ret = -errno;
         return ret;
@@ -62,6 +78,37 @@ static int hdfsSingleNameNodeConnect(struct NativeMiniDfsCluster *cl, hdfsFS *fs
     return 0;
 }
 
+static int doTestGetDefaultBlockSize(hdfsFS fs, const char *path)
+{
+    uint64_t blockSize;
+    int ret;
+
+    blockSize = hdfsGetDefaultBlockSize(fs);
+    if (blockSize < 0) {
+        ret = errno;
+        fprintf(stderr, "hdfsGetDefaultBlockSize failed with error %d\n", ret);
+        return ret;
+    } else if (blockSize != TLH_DEFAULT_BLOCK_SIZE) {
+        fprintf(stderr, "hdfsGetDefaultBlockSize got %"PRId64", but we "
+                "expected %d\n", blockSize, TLH_DEFAULT_BLOCK_SIZE);
+        return EIO;
+    }
+
+    blockSize = hdfsGetDefaultBlockSizeAtPath(fs, path);
+    if (blockSize < 0) {
+        ret = errno;
+        fprintf(stderr, "hdfsGetDefaultBlockSizeAtPath(%s) failed with "
+                "error %d\n", path, ret);
+        return ret;
+    } else if (blockSize != TLH_DEFAULT_BLOCK_SIZE) {
+        fprintf(stderr, "hdfsGetDefaultBlockSizeAtPath(%s) got "
+                "%"PRId64", but we expected %d\n", 
+                path, blockSize, TLH_DEFAULT_BLOCK_SIZE);
+        return EIO;
+    }
+    return 0;
+}
+
 static int doTestHdfsOperations(struct tlhThreadInfo *ti, hdfsFS fs)
 {
     char prefix[256], tmp[256];
@@ -77,6 +124,8 @@ static int doTestHdfsOperations(struct tlhThreadInfo *ti, hdfsFS fs)
     EXPECT_ZERO(hdfsCreateDirectory(fs, prefix));
     snprintf(tmp, sizeof(tmp), "%s/file", prefix);
 
+    EXPECT_ZERO(doTestGetDefaultBlockSize(fs, prefix));
+
     /* There should not be any file to open for reading. */
     EXPECT_NULL(hdfsOpenFile(fs, tmp, O_RDONLY, 0, 0, 0));