svnadmin dump — Dump the contents of the filesystem to stdout.
Dump the contents of the filesystem to stdout in a
“dump file” portable format, sending feedback to
stderr. Dump revisions
LOWER rev through
UPPER rev. If no revisions are given, dump all
revision trees. If only LOWER is given, dump
that one revision tree. See 第 4.5 节 “版本库数据的移植”
for a practical use.
By default, the Subversion dump stream contains a single revision (the first revision in the requested revision range) in which every file and directory in the repository in that revision is presented as though that whole tree was added at once, followed by other revisions (the remainder of the revisions in the requested range), which contain only the files and directories that were modified in those revisions. For a modified file, the complete full-text representation of its contents, as well as all of its properties, are presented in the dump file; for a directory, all of its properties are presented.
Two useful options modify the dump file generator's behavior. The first is
the --incremental option, which simply causes that first
revision in the dump stream to contain only the files and directories
modified in that revision, instead of being presented as the addition of a
new tree, and in exactly the same way that every other revision in the dump
file is presented. This is useful for generating a relatively small dump
file to be loaded into another repository that already has the files and
directories that exist in the original repository.
The second useful option is --deltas. This option causes
svnadmin dump to, instead of emitting full-text
representations of file contents and property lists, emit only deltas of
those items against their previous versions. This reduces (in some cases,
drastically) the size of the dump file that svnadmin dump
creates. There are, however, disadvantages to using this
option—deltified dump files are more CPU-intensive to create, cannot
be operated on by svndumpfilter, and tend not to compress
as well as their nondeltified counterparts when using third-party tools such
as gzip and bzip2.