##// END OF EJS Templates
exchangev2: fetch manifest revisions...
exchangev2: fetch manifest revisions Now that the server has support for retrieving manifest data, we can implement the client bits to call it. We teach the changeset fetching code to capture the manifest revisions that are encountered on incoming changesets. We then feed this into a new function which filters out known manifests and then batches up manifest data requests to the server. This is different from the previous wire protocol in a few notable ways. First, the client fetches manifest data separately and explicitly. Before, we'd ask the server for data pertaining to some changesets (via a "getbundle" command) and manifests (and files) would be sent automatically. Providing an API for looking up just manifest data separately gives clients much more flexibility for manifest management. For example, a client may choose to only fetch manifest data on demand instead of prefetching it (i.e. partial clone). Second, we send N commands to the server for manifest retrieval instead of 1. This property has a few nice side-effects. One is that the deterministic nature of the requests lends itself to server-side caching. For example, say the remote has 50,000 manifests. If the server is configured to cache responses, each time a new commit arrives, you will have a cache miss and need to regenerate all outgoing data. But if you makes N requests requesting 10,000 manifests each, a new commit will still yield cache hits on the initial, unchanged manifest batches/requests. A derived benefit from these properties is that resumable clone is conceptually simpler to implement. When making a monolithic request for all of the repository data, recovering from an interrupted clone is hard because the server was in the driver's seat and was maintaining state about all the data that needed transferred. With the client driving fetching, the client can persist the set of unfetched entities and retry/resume a fetch if something goes wrong. Or we can fetch all data N changesets at a time and slowly build up a repository. This approach is drastically easier to implement when we have server APIs exposing low-level repository primitives (such as manifests and files). We don't yet support tree manifests. But it should be possible to implement that with the existing wire protocol command. Differential Revision: https://phab.mercurial-scm.org/D4489

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osutilbuild.py
102 lines | 2.4 KiB | text/x-python | PythonLexer
from __future__ import absolute_import
import cffi
ffi = cffi.FFI()
ffi.set_source("mercurial.cffi._osutil", """
#include <sys/attr.h>
#include <sys/vnode.h>
#include <unistd.h>
#include <fcntl.h>
#include <time.h>
typedef struct val_attrs {
uint32_t length;
attribute_set_t returned;
attrreference_t name_info;
fsobj_type_t obj_type;
struct timespec mtime;
uint32_t accessmask;
off_t datalength;
} __attribute__((aligned(4), packed)) val_attrs_t;
""", include_dirs=['mercurial'])
ffi.cdef('''
typedef uint32_t attrgroup_t;
typedef struct attrlist {
uint16_t bitmapcount; /* number of attr. bit sets in list */
uint16_t reserved; /* (to maintain 4-byte alignment) */
attrgroup_t commonattr; /* common attribute group */
attrgroup_t volattr; /* volume attribute group */
attrgroup_t dirattr; /* directory attribute group */
attrgroup_t fileattr; /* file attribute group */
attrgroup_t forkattr; /* fork attribute group */
...;
};
typedef struct attribute_set {
...;
} attribute_set_t;
typedef struct attrreference {
int attr_dataoffset;
int attr_length;
...;
} attrreference_t;
typedef int ... off_t;
typedef struct val_attrs {
uint32_t length;
attribute_set_t returned;
attrreference_t name_info;
uint32_t obj_type;
struct timespec mtime;
uint32_t accessmask;
off_t datalength;
...;
} val_attrs_t;
/* the exact layout of the above struct will be figured out during build time */
typedef int ... time_t;
typedef struct timespec {
time_t tv_sec;
...;
};
int getattrlist(const char* path, struct attrlist * attrList, void * attrBuf,
size_t attrBufSize, unsigned int options);
int getattrlistbulk(int dirfd, struct attrlist * attrList, void * attrBuf,
size_t attrBufSize, uint64_t options);
#define ATTR_BIT_MAP_COUNT ...
#define ATTR_CMN_NAME ...
#define ATTR_CMN_OBJTYPE ...
#define ATTR_CMN_MODTIME ...
#define ATTR_CMN_ACCESSMASK ...
#define ATTR_CMN_ERROR ...
#define ATTR_CMN_RETURNED_ATTRS ...
#define ATTR_FILE_DATALENGTH ...
#define VREG ...
#define VDIR ...
#define VLNK ...
#define VBLK ...
#define VCHR ...
#define VFIFO ...
#define VSOCK ...
#define S_IFMT ...
int open(const char *path, int oflag, int perm);
int close(int);
#define O_RDONLY ...
''')
if __name__ == '__main__':
ffi.compile()