file-upload - DropboxSDK : What's the benefit of uploadFileChunk: over uploadFile: in DBRestClient?

Question

序言:

如果您觉得这可能与Using iOS Dropbox SDK to do a Chunked Upload of Core Data重复那么我不得不让你失望了 - 我的问题不是如何上传。相反，我的问题是比较两种上传方法的优缺点。其他问题没有涵盖这一点，所以我的问题不是重复的。

问题:

对于使用 DropboxSDK 上传文件，有两种不同的方法。评论只说一种方法“对于大于几兆字节的文件更好”。具体有哪些好处呢？第二种方法似乎比较难用，那么它有什么优点呢？

以下是 iOS DropboxSDK 中的两种方法:

1. 上传文件:

/* Uploads a file that will be named filename to the given path on the server. sourcePath is the`
   full path of the file you want to upload. If you are modifying a file, parentRev represents the
   rev of the file before you modified it as returned from the server. If you are uploading a new
   file set parentRev to nil. */
- (void)uploadFile:(NSString *)filename toPath:(NSString *)path withParentRev:(NSString *)parentRev
    fromPath:(NSString *)sourcePath;

2. uploadFileChunk:

/* These calls allow you to upload files in chunks, which is better for file larger than a few megabytes.
   You can append bytes to the file using -[DBRestClient uploadFileChunk:offset:uploadId:] and then call
   -[DBRestClient uploadFile:toPath:withParentRev:fromUploadId:] to turn the bytes appended at that uploadId
   into an actual file in the user's Dropbox.
   Use a nil uploadId to start uploading a new file. */
- (void)uploadFileChunk:(NSString *)uploadId offset:(unsigned long long)offset fromPath:(NSString *)localPath;

Answer 1

参见https://www.dropbox.com/developers/core/docs#files_put和 https://www.dropbox.com/developers/core/docs#chunked-upload .

前者允许最多 150MB 并在单个 HTTP 请求中写入文件，因此如果不从文件开头重新开始，就无法恢复失败的上传。

后者允许任何大小，并且任何失败的上传都可以从中断处恢复(只需发送下一个 block )。