3cf0bed836
guest-sync leaves it as an exercise to the user as to how to reliably obtain the response to guest-sync if the client had previously read in a partial response (due qemu-ga previously being restarted mid-"sentence" due to reboot, forced restart, etc). qemu-ga handles this situation on its end by having a client precede their guest-sync request with a 0xFF byte (invalid UTF-8), which qemu-ga/QEMU JSON parsers will treat as a flush event. Thus we can reliably flush the qemu-ga parser state in preparation for receiving the guest-sync request. guest-sync-delimited provides the same functionality for a client: when a guest-sync-delimited is issued, qemu-ga will precede it's response with a 0xFF byte that the client can use as an indicator to flush its buffer/parser state in preparation for reliably receiving the guest-sync-delimited response. It is also useful as an optimization for clients, since, after issuing a guest-sync-delimited, clients can safely discard all stale data read from the channel until the 0xFF is found. More information available on the wiki: http://wiki.qemu.org/Features/QAPI/GuestAgent#QEMU_Guest_Agent_Protocol Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
35 lines
1.1 KiB
C
35 lines
1.1 KiB
C
/*
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* QEMU Guest Agent core declarations
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*
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* Copyright IBM Corp. 2011
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*
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* Authors:
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* Adam Litke <aglitke@linux.vnet.ibm.com>
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* Michael Roth <mdroth@linux.vnet.ibm.com>
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*
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* This work is licensed under the terms of the GNU GPL, version 2 or later.
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* See the COPYING file in the top-level directory.
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*/
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#include "qapi/qmp-core.h"
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#include "qemu-common.h"
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#define QGA_VERSION "1.0"
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#define QGA_READ_COUNT_DEFAULT 4096
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typedef struct GAState GAState;
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typedef struct GACommandState GACommandState;
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extern GAState *ga_state;
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void ga_command_state_init(GAState *s, GACommandState *cs);
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void ga_command_state_add(GACommandState *cs,
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void (*init)(void),
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void (*cleanup)(void));
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void ga_command_state_init_all(GACommandState *cs);
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void ga_command_state_cleanup_all(GACommandState *cs);
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GACommandState *ga_command_state_new(void);
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bool ga_logging_enabled(GAState *s);
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void ga_disable_logging(GAState *s);
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void ga_enable_logging(GAState *s);
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void slog(const gchar *fmt, ...);
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void ga_set_response_delimited(GAState *s);
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