##// END OF EJS Templates
wireprotov2peer: stream decoded responses...
wireprotov2peer: stream decoded responses Previously, wire protocol version 2 would buffer all response data. Only once all data was received did we CBOR decode it and resolve the future associated with the command. This was obviously not desirable. In future commits that introduce large response payloads, this caused significant memory bloat and slowed down client operations due to waiting on the server. This commit refactors the response handling code so that response data can be streamed. Command response objects now contain a buffered CBOR decoder. As new data arrives, it is fed into the decoder. Decoded objects are made available to the generator as they are decoded. Because there is a separate thread processing incoming frames and feeding data into the response object, there is the potential for race conditions when mutating response objects. So a lock has been added to guard access to critical state variables. Because the generator emitting decoded objects needs to wait on those objects to become available, we've added an Event for the generator to wait on so it doesn't busy loop. This does mean there is the potential for deadlocks. And I'm pretty sure they can occur in some scenarios. We already have a handful of TODOs around this. But I've added some more. Fixing this will likely require moving the background thread receiving frames into clienthandler. We likely would have done this anyway when implementing the client bits for the SSH transport. Test output changes because the initial CBOR map holding the overall response state is now always handled internally by the response object. Differential Revision: https://phab.mercurial-scm.org/D4474

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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()