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Diffstat (limited to 'man/man3/venti-client.3')
| -rw-r--r-- | man/man3/venti-client.3 | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/man/man3/venti-client.3 b/man/man3/venti-client.3 new file mode 100644 index 00000000..ec18fc4e --- /dev/null +++ b/man/man3/venti-client.3 @@ -0,0 +1,194 @@ +.TH VENTI-CLIENT 3 +.SH NAME +vtconnect, vthello, vtread, vtwrite, vtreadpacket, vtwritepacket, vtsync, vtping, vtrpc, ventidoublechecksha1 \- Venti client +.SH SYNOPSIS +.ft L +#include <u.h> +.br +#include <libc.h> +.br +#include <venti.h> +.ta +\w'\fLextern int 'u +\w'\fLxxxxxxxx'u +.PP +.B +Packet* vtrpc(VtConn *z, Packet *p) +.PP +.B +int vthello(VtConn *z) +.PP +.B +int vtconnect(VtConn *z) +.PP +.B +int vtread(VtConn *z, uchar score[VtScoreSize], +.br +.B + uint type, uchar *buf, int n) +.PP +.B +int vtwrite(VtConn *z, uchar score[VtScoreSize], +.br +.B + uint type, uchar *buf, int n) +.PP +.B +Packet* vtreadpacket(VtConn *z, uchar score[VtScoreSize], +.br +.B + uint type, int n) +.PP +.B +int vtwritepacket(VtConn *z, uchar score[VtScoreSize], +.br +.B + uint type, Packet *p) +.PP +.B +int vtsync(VtConn *z) +.PP +.B +int vtping(VtConn *z) +.PP +.B +extern int ventidoublechecksha1; /* default 1 */ +.SH DESCRIPTION +These routines execute the client side of the +.IR venti (7) +protocol. +.PP +.I Vtrpc +executes a single Venti RPC transaction, sending the request +packet +.IR p +and then waiting for and returning the response packet. +.I Vtrpc +will set the tag in the packet. +.I Vtrpc +frees +.IR p , +even on error. +.I Vtrpc +is typically called only indirectly, via the functions below. +.PP +.I Vthello +executes a +.B hello +transaction +(see +.IR venti (7)), setting +.IB z -> sid +to the name used by the server. +.I Vthello +is typically called only indirectly, via +.IR vtconnect . +.PP +.I Vtconnect +calls +.I vtversion +(see +.IR venti-conn (3)) +and +.IR vthello , +in that order, returning success only +if both succeed. +This sequence (calling +.I vtversion +and then +.IR vthello ) +must be done before the functions below can be called. +.PP +.I Vtread +reads the block with the given +.I score +and +.I type +from the server, +writes the returned data +to +.IR buf , +and returns the number of bytes retrieved. +If the stored block has size larger than +.IR n , +.I vtread +does not modify +.I buf +and +returns an error. +.PP +.I Vtwrite +writes the +.I n +bytes in +.I buf +with type +.IR type , +setting +.IR score . +.PP +.I Vtreadpacket +and +.I vtwritepacket +are like +.I vtread +and +.I vtwrite +but return or accept the block contents in the +form of a +.BR Packet . +They avoid making a copy of the data. +.PP +.I Vtsync +causes the server to flush all pending write requests +to disk before returning. +.PP +.I Vtping +executes a ping transaction with the server. +.PP +By default, +.I vtread +and +.I vtreadpacket +check that the SHA1 hash of the returned data +matches the requested +.IR score , +and +.I vtwrite +and +.I vtwritepacket +check that the returned +.I score +matches the SHA1 hash of the written data. +Setting +.I ventidoublechecksha1 +to zero disables these extra checks, +mainly for benchmarking purposes. +Doing so in production code is not recommended. +.PP +These functions can be called from multiple threads +or procs simultaneously to issue requests +in parallel. +Programs that issue requests from multiple threads +in the same proc should start separate procs running +.I vtsendproc +and +.I vtrecvproc +as described in +.IR venti-conn (3). +.SH SOURCE +.B \*9/src/libventi +.SH SEE ALSO +.IR venti (1), +.IR venti (3), +.IR venti-conn (3), +.IR venti-packet (3), +.IR venti (7) +.SH DIAGNOSTICS +.I Vtrpc +and +.I vtpacket +return nil on error. +The other routines return \-1 on error. +.PP +.I Vtwrite +returns 0 on success, +meaning it wrote the entire block. |