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| author | Junio C Hamano <gitster@pobox.com> | 2025-12-16 11:08:34 +0900 |
|---|---|---|
| committer | Junio C Hamano <gitster@pobox.com> | 2025-12-16 11:08:34 +0900 |
| commit | dbe54273a707406409fa386db5b105557b31a831 (patch) | |
| tree | 0def4e76638eff5ca5628d3cb2d0acb157c7bf37 /odb/streaming.h | |
| parent | d8af7cadaa79d5837d73ec949e10b57dedb43e9b (diff) | |
| parent | 7b940286527ec2175dffbb317f47e080bb37cf3e (diff) | |
| download | git-dbe54273a707406409fa386db5b105557b31a831.tar.gz | |
Merge branch 'ps/object-read-stream'
The "git_istream" abstraction has been revamped to make it easier
to interface with pluggable object database design.
* ps/object-read-stream:
streaming: drop redundant type and size pointers
streaming: move into object database subsystem
streaming: refactor interface to be object-database-centric
streaming: move logic to read packed objects streams into backend
streaming: move logic to read loose objects streams into backend
streaming: make the `odb_read_stream` definition public
streaming: get rid of `the_repository`
streaming: rely on object sources to create object stream
packfile: introduce function to read object info from a store
streaming: move zlib stream into backends
streaming: create structure for filtered object streams
streaming: create structure for packed object streams
streaming: create structure for loose object streams
streaming: create structure for in-core object streams
streaming: allocate stream inside the backend-specific logic
streaming: explicitly pass packfile info when streaming a packed object
streaming: propagate final object type via the stream
streaming: drop the `open()` callback function
streaming: rename `git_istream` into `odb_read_stream`
Diffstat (limited to 'odb/streaming.h')
| -rw-r--r-- | odb/streaming.h | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/odb/streaming.h b/odb/streaming.h new file mode 100644 index 0000000000..c7861f7e13 --- /dev/null +++ b/odb/streaming.h @@ -0,0 +1,67 @@ +/* + * Copyright (c) 2011, Google Inc. + */ +#ifndef STREAMING_H +#define STREAMING_H 1 + +#include "object.h" + +struct object_database; +struct odb_read_stream; +struct stream_filter; + +typedef int (*odb_read_stream_close_fn)(struct odb_read_stream *); +typedef ssize_t (*odb_read_stream_read_fn)(struct odb_read_stream *, char *, size_t); + +/* + * A stream that can be used to read an object from the object database without + * loading all of it into memory. + */ +struct odb_read_stream { + odb_read_stream_close_fn close; + odb_read_stream_read_fn read; + enum object_type type; + unsigned long size; /* inflated size of full object */ +}; + +/* + * Create a new object stream for the given object database. An optional filter + * can be used to transform the object's content. + * + * Returns the stream on success, a `NULL` pointer otherwise. + */ +struct odb_read_stream *odb_read_stream_open(struct object_database *odb, + const struct object_id *oid, + struct stream_filter *filter); + +/* + * Close the given read stream and release all resources associated with it. + * Returns 0 on success, a negative error code otherwise. + */ +int odb_read_stream_close(struct odb_read_stream *stream); + +/* + * Read data from the stream into the buffer. Returns 0 on EOF and the number + * of bytes read on success. Returns a negative error code in case reading from + * the stream fails. + */ +ssize_t odb_read_stream_read(struct odb_read_stream *stream, void *buf, size_t len); + +/* + * Look up the object by its ID and write the full contents to the file + * descriptor. The object must be a blob, or the function will fail. When + * provided, the filter is used to transform the blob contents. + * + * `can_seek` should be set to 1 in case the given file descriptor can be + * seek(3p)'d on. This is used to support files with holes in case a + * significant portion of the blob contains NUL bytes. + * + * Returns a negative error code on failure, 0 on success. + */ +int odb_stream_blob_to_fd(struct object_database *odb, + int fd, + const struct object_id *oid, + struct stream_filter *filter, + int can_seek); + +#endif /* STREAMING_H */ |
