HDFS-9541. Add hdfsStreamBuilder API to libhdfs to support defaultBlockSizes greater than 2 GB. Contributed by Colin Patrick McCabe.

Change-Id: Ifce1b9be534dc8f7e9d2634cd60e423921b9810f

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

@@ -838,6 +838,92 @@ static jthrowable getDefaultBlockSize(JNIEnv *env, jobject jFS,
 
 hdfsFile hdfsOpenFile(hdfsFS fs, const char *path, int flags,
                       int bufferSize, short replication, tSize blockSize)
+{
+    struct hdfsStreamBuilder *bld = hdfsStreamBuilderAlloc(fs, path, flags);
+    if (bufferSize != 0) {
+      hdfsStreamBuilderSetBufferSize(bld, bufferSize);
+    }
+    if (replication != 0) {
+      hdfsStreamBuilderSetReplication(bld, replication);
+    }
+    if (blockSize != 0) {
+      hdfsStreamBuilderSetDefaultBlockSize(bld, blockSize);
+    }
+    return hdfsStreamBuilderBuild(bld);
+}
+
+struct hdfsStreamBuilder {
+    hdfsFS fs;
+    int flags;
+    int32_t bufferSize;
+    int16_t replication;
+    int64_t defaultBlockSize;
+    char path[1];
+};
+
+struct hdfsStreamBuilder *hdfsStreamBuilderAlloc(hdfsFS fs,
+                                            const char *path, int flags)
+{
+    int path_len = strlen(path);
+    struct hdfsStreamBuilder *bld;
+
+    // sizeof(hdfsStreamBuilder->path) includes one byte for the string
+    // terminator
+    bld = malloc(sizeof(struct hdfsStreamBuilder) + path_len);
+    if (!bld) {
+        errno = ENOMEM;
+        return NULL;
+    }
+    bld->fs = fs;
+    bld->flags = flags;
+    bld->bufferSize = 0;
+    bld->replication = 0;
+    bld->defaultBlockSize = 0;
+    memcpy(bld->path, path, path_len);
+    bld->path[path_len] = '\0';
+    return bld;
+}
+
+void hdfsStreamBuilderFree(struct hdfsStreamBuilder *bld)
+{
+    free(bld);
+}
+
+int hdfsStreamBuilderSetBufferSize(struct hdfsStreamBuilder *bld,
+                                   int32_t bufferSize)
+{
+    if ((bld->flags & O_ACCMODE) != O_WRONLY) {
+        errno = EINVAL;
+        return -1;
+    }
+    bld->bufferSize = bufferSize;
+    return 0;
+}
+
+int hdfsStreamBuilderSetReplication(struct hdfsStreamBuilder *bld,
+                                    int16_t replication)
+{
+    if ((bld->flags & O_ACCMODE) != O_WRONLY) {
+        errno = EINVAL;
+        return -1;
+    }
+    bld->replication = replication;
+    return 0;
+}
+
+int hdfsStreamBuilderSetDefaultBlockSize(struct hdfsStreamBuilder *bld,
+                                         int64_t defaultBlockSize)
+{
+    if ((bld->flags & O_ACCMODE) != O_WRONLY) {
+        errno = EINVAL;
+        return -1;
+    }
+    bld->defaultBlockSize = defaultBlockSize;
+    return 0;
+}
+
+static hdfsFile hdfsOpenFileImpl(hdfsFS fs, const char *path, int flags,
+                  int32_t bufferSize, int16_t replication, int64_t blockSize)
 {
     /*
       JAVA EQUIVALENT:
@@ -1037,6 +1123,16 @@ done:
     return file;
 }
 
+hdfsFile hdfsStreamBuilderBuild(struct hdfsStreamBuilder *bld)
+{
+    hdfsFile file = hdfsOpenFileImpl(bld->fs, bld->path, bld->flags,
+                  bld->bufferSize, bld->replication, bld->defaultBlockSize);
+    int prevErrno = errno;
+    hdfsStreamBuilderFree(bld);
+    errno = prevErrno;
+    return file;
+}
+
 int hdfsTruncateFile(hdfsFS fs, const char* path, tOffset newlength)
 {
     jobject jFS = (jobject)fs;

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

@@ -80,6 +80,7 @@ extern  "C" {
         kObjectKindFile = 'F',
         kObjectKindDirectory = 'D',
     } tObjectKind;
+    struct hdfsStreamBuilder;
 
 
     /**
@@ -376,9 +377,11 @@ extern  "C" {
     LIBHDFS_EXTERNAL
     int hdfsDisconnect(hdfsFS fs);
         
-
     /** 
      * hdfsOpenFile - Open a hdfs file in given mode.
+     * @deprecated    Use the hdfsStreamBuilder functions instead.
+     * This function does not support setting block sizes bigger than 2 GB.
+     *
      * @param fs The configured filesystem handle.
      * @param path The full path to the file.
      * @param flags - an | of bits/fcntl.h file flags - supported flags are O_RDONLY, O_WRONLY (meaning create or overwrite i.e., implies O_TRUNCAT), 
@@ -388,13 +391,95 @@ extern  "C" {
      * @param replication Block replication - pass 0 if you want to use
      * the default configured values.
      * @param blocksize Size of block - pass 0 if you want to use the
-     * default configured values.
+     * default configured values.  Note that if you want a block size bigger
+     * than 2 GB, you must use the hdfsStreamBuilder API rather than this
+     * deprecated function.
      * @return Returns the handle to the open file or NULL on error.
      */
     LIBHDFS_EXTERNAL
     hdfsFile hdfsOpenFile(hdfsFS fs, const char* path, int flags,
                           int bufferSize, short replication, tSize blocksize);
 
+    /**
+     * hdfsStreamBuilderAlloc - Allocate an HDFS stream builder.
+     *
+     * @param fs The configured filesystem handle.
+     * @param path The full path to the file.  Will be deep-copied.
+     * @param flags The open flags, as in hdfsOpenFile.
+     * @return Returns the hdfsStreamBuilder, or NULL on error.
+     */
+    LIBHDFS_EXTERNAL
+    struct hdfsStreamBuilder *hdfsStreamBuilderAlloc(hdfsFS fs,
+                                      const char *path, int flags);
+
+    /**
+     * hdfsStreamBuilderFree - Free an HDFS file builder.
+     *
+     * It is normally not necessary to call this function since
+     * hdfsStreamBuilderBuild frees the builder.
+     *
+     * @param bld The hdfsStreamBuilder to free.
+     */
+    LIBHDFS_EXTERNAL
+    void hdfsStreamBuilderFree(struct hdfsStreamBuilder *bld);
+
+    /**
+     * hdfsStreamBuilderSetBufferSize - Set the stream buffer size.
+     *
+     * @param bld The hdfs stream builder.
+     * @param bufferSize The buffer size to set.
+     *
+     * @return 0 on success, or -1 on error.  Errno will be set on error.
+     */
+    LIBHDFS_EXTERNAL
+    int hdfsStreamBuilderSetBufferSize(struct hdfsStreamBuilder *bld,
+                                       int32_t bufferSize);
+
+    /**
+     * hdfsStreamBuilderSetReplication - Set the replication for the stream.
+     * This is only relevant for output streams, which will create new blocks.
+     *
+     * @param bld The hdfs stream builder.
+     * @param replication The replication to set.
+     *
+     * @return 0 on success, or -1 on error.  Errno will be set on error.
+     *              If you call this on an input stream builder, you will get
+     *              EINVAL, because this configuration is not relevant to input
+     *              streams.
+     */
+    LIBHDFS_EXTERNAL
+    int hdfsStreamBuilderSetReplication(struct hdfsStreamBuilder *bld,
+                                        int16_t replication);
+
+    /**
+     * hdfsStreamBuilderSetDefaultBlockSize - Set the default block size for
+     * the stream.  This is only relevant for output streams, which will create
+     * new blocks.
+     *
+     * @param bld The hdfs stream builder.
+     * @param defaultBlockSize The default block size to set.
+     *
+     * @return 0 on success, or -1 on error.  Errno will be set on error.
+     *              If you call this on an input stream builder, you will get
+     *              EINVAL, because this configuration is not relevant to input
+     *              streams.
+     */
+    LIBHDFS_EXTERNAL
+    int hdfsStreamBuilderSetDefaultBlockSize(struct hdfsStreamBuilder *bld,
+                                       int64_t defaultBlockSize);
+
+    /**
+     * hdfsStreamBuilderBuild - Build the stream by calling open or create.
+     *
+     * @param bld The hdfs stream builder.  This pointer will be freed, whether
+     *            or not the open succeeds.
+     *
+     * @return the stream pointer on success, or NULL on error.  Errno will be
+     * set on error.
+     */
+    LIBHDFS_EXTERNAL
+    hdfsFile hdfsStreamBuilderBuild(struct hdfsStreamBuilder *bld);
+
     /**
      * hdfsTruncateFile - Truncate a hdfs file to given lenght.
      * @param fs The configured filesystem handle.

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

@@ -53,6 +53,9 @@ Release 2.9.0 - UNRELEASED
     HDFS-9094. Add command line option to ask NameNode reload
     configuration. (Xiaobing Zhou via Arpit Agarwal)
 
+    HDFS-9541. Add hdfsStreamBuilder API to libhdfs to support defaultBlockSizes
+    greater than 2 GB. (cmccabe via zhz)
+
   OPTIMIZATIONS
 
   BUG FIXES