| .TH VENTI-LOG 3 |
| .SH NAME |
| VtLog, |
| VtLogChunk, |
| vtlog, |
| vtlogclose, |
| vtlogdump, |
| vtlognames, |
| vtlogopen, |
| vtlogprint, |
| vtlogremove, |
| vtlogopen, |
| ventilogging \- Venti logs |
| .SH SYNOPSIS |
| .ft L |
| #include <u.h> |
| .br |
| #include <libc.h> |
| .br |
| #include <venti.h> |
| .ta +\w'\fLVtLog* 'u |
| .PP |
| .B |
| VtLog* vtlogopen(char *name, uint size); |
| .PP |
| .B |
| void vtlogprint(VtLog *log, char *fmt, ...); |
| .PP |
| .B |
| void vtlogclose(VtLog *log); |
| .PP |
| .B |
| void vtlog(char *name, char *fmt, ...); |
| .PP |
| .B |
| void vtlogremove(char *name); |
| .PP |
| .B |
| char** vtlognames(int *n); |
| .PP |
| .B |
| void vtlogdump(int fd, VtLog *log); |
| .PP |
| .B |
| extern int ventilogging; /* default 0 */ |
| .PP |
| .B |
| extern char *VtServerLog; /* "libventi/server" */ |
| .SH DESCRIPTION |
| These routines provide an in-memory circular log |
| structure used by the Venti library and the Venti server |
| to record events for debugging purposes. |
| The logs are named by UTF strings. |
| .PP |
| .I Vtlogopen |
| returns a reference to the log with the given |
| .I name . |
| If a log with that name does not exist and |
| .I size |
| is non-zero, |
| .I vtlogopen |
| creates a new log capable of holding at |
| least |
| .I size |
| bytes and returns it. |
| .I Vtlogclose |
| releases the reference returned by |
| .IR vtlogopen . |
| .PP |
| .I Vtlogprint |
| writes to |
| .IR log , |
| which must be open. |
| .PP |
| .I Vtlog |
| is a convenient packaging of |
| .I vtlogopen |
| followed by |
| .I vtlogprint |
| and |
| .IR vtlogclose . |
| .PP |
| .I Vtlogremove |
| removes the log with the given |
| .IR name , |
| freeing any associated storage. |
| .PP |
| .I Vtlognames |
| returns a list of the names of all the logs. |
| The length of the list is returned in |
| .BI * n \fR. |
| The list |
| should be freed |
| by calling |
| .I vtfree |
| on the returned pointer. |
| The strings in the list will be freed by this call as well. |
| (It is an error to call |
| .I vtfree |
| on any of the strings in the list.) |
| .PP |
| .I Vtlogdump |
| prints |
| .IR log , |
| which must be open, to the file descriptor |
| .IR fd . |
| .PP |
| If |
| .I ventilogging |
| is set to zero (the default), |
| .I vtlognames |
| and |
| .I vtlogdump |
| can inspect existing logs, but |
| .I vtlogopen |
| always returns nil |
| and |
| .I vtlog |
| is a no-op. |
| The other functions are no-ops when |
| passed nil log structures. |
| .PP |
| The server library |
| (see |
| .IR venti-conn (3) |
| and |
| .IR venti-server (3)) |
| writes debugging information to the log named |
| .IR VtServerLog , |
| which defaults to the string |
| .RB ` libventi/server '. |
| .SH SOURCE |
| .B \*9/src/libventi |
| .SH SEE ALSO |
| .IR venti (3), |
| .IR venti (8) |
