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| author | Patrick Steinhardt <ps@pks.im> | 2025-11-23 19:59:43 +0100 |
|---|---|---|
| committer | Junio C Hamano <gitster@pobox.com> | 2025-11-23 12:56:46 -0800 |
| commit | 1599b68d5e960a12f5ac624f81c70ece317db5a6 (patch) | |
| tree | d5ed95793921811cc11010b5f92d239d810cc351 /odb/streaming.h | |
| parent | 378ec56beba161abbef6e2c87d9bc2ac43c355f3 (diff) | |
| download | git-1599b68d5e960a12f5ac624f81c70ece317db5a6.tar.gz | |
streaming: move into object database subsystem
The "streaming" terminology is somewhat generic, so it may not be
immediately obvious that "streaming.{c,h}" is specific to the object
database. Rectify this by moving it into the "odb/" directory so that it
can be immediately attributed to the object subsystem.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'odb/streaming.h')
| -rw-r--r-- | odb/streaming.h | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/odb/streaming.h b/odb/streaming.h new file mode 100644 index 0000000000..7cb55213b7 --- /dev/null +++ b/odb/streaming.h @@ -0,0 +1,70 @@ +/* + * 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. Populates the type + * and size pointers with the object's info. 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, + enum object_type *type, + unsigned long *size, + 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 */ |