Daniel P. Berrange wrote: [Tue Oct 06 2009, 05:00:55AM EDT]
Having looked at the wway the next patch uses these, I think it'd be nicer to change the contract to just be
extern char *virLogGetFilters(void); extern char *virLogGetOutputs(void);
Heh, that's how I wrote it the first time. Then I changed it to make use of the virBuffer API, and tried to follow precedent with the rest of libvirt. The code is not really doing much with the string, maybe virBuffer is overkill?
The general rule to try & follow is that if you just have a single printf style call to make, then use virAsprintf. If you have several printf/strcat calls to make, then use virBuffer.
In this particular case, its fine to use virBuffer for your internal impl - I just thing its better to not include it in the public API, convert the virBuffer into a char * for the return value
That makes sense. Does this look good now? --- When configuring logging settings, keep more information about the output destination. Add accessors to retrieve the filter and output settings in the original string form; this to be used to set up environment for a child process that also logs. Open output files O_APPEND so child can also write -- was there a reason to truncate them? Note this patch changes the API for virLogDefineOutput(), which is part of the internal libvirt API, but is currently only used within logging.c. --- src/libvirt_private.syms | 2 + src/util/logging.c | 112 +++++++++++++++++++++++++++++++++++++++++++--- src/util/logging.h | 14 +++++- 3 files changed, 119 insertions(+), 9 deletions(-) diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms index fb9b9ae..732fd08 100644 --- a/src/libvirt_private.syms +++ b/src/libvirt_private.syms @@ -253,6 +253,8 @@ virRegisterSecretDriver; virLogMessage; virLogGetNbFilters; virLogGetNbOutputs; +virLogGetFilters; +virLogGetOutputs; virLogGetDefaultPriority; virLogSetDefaultPriority; virLogSetFromEnv; diff --git a/src/util/logging.c b/src/util/logging.c index 07c2b0e..4899de6 100644 --- a/src/util/logging.c +++ b/src/util/logging.c @@ -37,6 +37,7 @@ #include "logging.h" #include "memory.h" #include "util.h" +#include "buf.h" #include "threads.h" /* @@ -109,6 +110,8 @@ struct _virLogOutput { virLogOutputFunc f; virLogCloseFunc c; int priority; + virLogDestination dest; + const char *name; }; typedef struct _virLogOutput virLogOutput; typedef virLogOutput *virLogOutputPtr; @@ -138,6 +141,17 @@ static void virLogUnlock(void) virMutexUnlock(&virLogMutex); } +static const char *virLogOutputString(virLogDestination ldest) { + switch (ldest) { + case VIR_LOG_TO_STDERR: + return("stderr"); + case VIR_LOG_TO_SYSLOG: + return("syslog"); + case VIR_LOG_TO_FILE: + return("file"); + } + return("unknown"); +} static const char *virLogPriorityString(virLogPriority lvl) { switch (lvl) { @@ -428,6 +442,7 @@ static int virLogResetOutputs(void) { for (i = 0;i < virLogNbOutputs;i++) { if (virLogOutputs[i].c != NULL) virLogOutputs[i].c(virLogOutputs[i].data); + VIR_FREE(virLogOutputs[i].name); } VIR_FREE(virLogOutputs); i = virLogNbOutputs; @@ -438,9 +453,11 @@ static int virLogResetOutputs(void) { /** * virLogDefineOutput: * @f: the function to call to output a message - * @f: the function to call to close the output (or NULL) + * @c: the function to call to close the output (or NULL) * @data: extra data passed as first arg to the function * @priority: minimal priority for this filter, use 0 for none + * @dest: where to send output of this priority + * @name: optional name data associated with an output * @flags: extra flag, currently unused * * Defines an output function for log messages. Each message once @@ -449,12 +466,22 @@ static int virLogResetOutputs(void) { * Returns -1 in case of failure or the output number if successful */ int virLogDefineOutput(virLogOutputFunc f, virLogCloseFunc c, void *data, - int priority, int flags ATTRIBUTE_UNUSED) { + int priority, int dest, const char *name, + int flags ATTRIBUTE_UNUSED) { int ret = -1; + char *ndup = NULL; if (f == NULL) return(-1); + if (dest == VIR_LOG_TO_SYSLOG || dest == VIR_LOG_TO_FILE) { + if (name == NULL) + return(-1); + ndup = strdup(name); + if (ndup == NULL) + return(-1); + } + virLogLock(); if (VIR_REALLOC_N(virLogOutputs, virLogNbOutputs + 1)) { goto cleanup; @@ -464,6 +491,8 @@ int virLogDefineOutput(virLogOutputFunc f, virLogCloseFunc c, void *data, virLogOutputs[ret].c = c; virLogOutputs[ret].data = data; virLogOutputs[ret].priority = priority; + virLogOutputs[ret].dest = dest; + virLogOutputs[ret].name = ndup; cleanup: virLogUnlock(); return(ret); @@ -577,7 +606,8 @@ static void virLogCloseFd(void *data) { } static int virLogAddOutputToStderr(int priority) { - if (virLogDefineOutput(virLogOutputToFd, NULL, (void *)2L, priority, 0) < 0) + if (virLogDefineOutput(virLogOutputToFd, NULL, (void *)2L, priority, + VIR_LOG_TO_STDERR, NULL, 0) < 0) return(-1); return(0); } @@ -585,11 +615,11 @@ static int virLogAddOutputToStderr(int priority) { static int virLogAddOutputToFile(int priority, const char *file) { int fd; - fd = open(file, O_CREAT | O_TRUNC | O_WRONLY, S_IRUSR | S_IWUSR); + fd = open(file, O_CREAT | O_APPEND | O_WRONLY, S_IRUSR | S_IWUSR); if (fd < 0) return(-1); if (virLogDefineOutput(virLogOutputToFd, virLogCloseFd, (void *)(long)fd, - priority, 0) < 0) { + priority, VIR_LOG_TO_FILE, file, 0) < 0) { close(fd); return(-1); } @@ -643,7 +673,7 @@ static int virLogAddOutputToSyslog(int priority, const char *ident) { openlog(current_ident, 0, 0); if (virLogDefineOutput(virLogOutputToSyslog, virLogCloseSyslog, NULL, - priority, 0) < 0) { + priority, VIR_LOG_TO_SYSLOG, ident, 0) < 0) { closelog(); VIR_FREE(current_ident); return(-1); @@ -682,6 +712,7 @@ static int virLogAddOutputToSyslog(int priority, const char *ident) { int virLogParseOutputs(const char *outputs) { const char *cur = outputs, *str; char *name; + char *abspath; int prio; int ret = -1; int count = 0; @@ -732,9 +763,14 @@ int virLogParseOutputs(const char *outputs) { name = strndup(str, cur - str); if (name == NULL) goto cleanup; - if (virLogAddOutputToFile(prio, name) == 0) + if (virFileAbsPath(name, &abspath) < 0) { + VIR_FREE(name); + return -1; /* skip warning here because setting was fine */ + } + if (virLogAddOutputToFile(prio, abspath) == 0) count++; VIR_FREE(name); + VIR_FREE(abspath); } else { goto cleanup; } @@ -813,6 +849,68 @@ int virLogGetDefaultPriority(void) { } /** + * virLogGetFilters: + * + * Returns a string listing the current filters, in the format originally + * specified in the config file or environment. Caller must free the + * result. + */ +char *virLogGetFilters(void) { + int i; + virBuffer filterbuf = VIR_BUFFER_INITIALIZER; + + virLogLock(); + for (i = 0; i < virLogNbFilters; i++) { + virBufferVSprintf(&filterbuf, "%d:%s ", virLogFilters[i].priority, + virLogFilters[i].match); + } + virLogUnlock(); + + if (virBufferError(&filterbuf)) + return NULL; + + return virBufferContentAndReset(&filterbuf); +} + +/** + * virLogGetOutputs: + * + * Returns a string listing the current outputs, in the format originally + * specified in the config file or environment. Caller must free the + * result. + */ +char *virLogGetOutputs(void) { + int i; + virBuffer outputbuf = VIR_BUFFER_INITIALIZER; + + virLogLock(); + for (i = 0; i < virLogNbOutputs; i++) { + int dest = virLogOutputs[i].dest; + if (i) + virBufferVSprintf(&outputbuf, " "); + switch (dest) { + case VIR_LOG_TO_SYSLOG: + case VIR_LOG_TO_FILE: + virBufferVSprintf(&outputbuf, "%d:%s:%s", + virLogOutputs[i].priority, + virLogOutputString(dest), + virLogOutputs[i].name); + break; + default: + virBufferVSprintf(&outputbuf, "%d:%s", + virLogOutputs[i].priority, + virLogOutputString(dest)); + } + } + virLogUnlock(); + + if (virBufferError(&outputbuf)) + return NULL; + + return virBufferContentAndReset(&outputbuf); +} + +/** * virLogGetNbFilters: * * Returns the current number of defined log filters. diff --git a/src/util/logging.h b/src/util/logging.h index 8b2b84c..49e2f6d 100644 --- a/src/util/logging.h +++ b/src/util/logging.h @@ -23,6 +23,7 @@ #define __VIRTLOG_H_ #include "internal.h" +#include "buf.h" /* * If configured with --enable-debug=yes then library calls @@ -79,6 +80,12 @@ typedef enum { #define VIR_LOG_DEFAULT VIR_LOG_WARN +typedef enum { + VIR_LOG_TO_STDERR = 1, + VIR_LOG_TO_SYSLOG, + VIR_LOG_TO_FILE, +} virLogDestination; + /** * virLogOutputFunc: * @category: the category for the message @@ -107,12 +114,15 @@ typedef void (*virLogCloseFunc) (void *data); extern int virLogGetNbFilters(void); extern int virLogGetNbOutputs(void); +extern char *virLogGetFilters(void); +extern char *virLogGetOutputs(void); extern int virLogGetDefaultPriority(void); extern int virLogSetDefaultPriority(int priority); extern void virLogSetFromEnv(void); extern int virLogDefineFilter(const char *match, int priority, int flags); -extern int virLogDefineOutput(virLogOutputFunc f, virLogCloseFunc c, - void *data, int priority, int flags); +extern int virLogDefineOutput(virLogOutputFunc f, virLogCloseFunc c, void *data, + int priority, int dest, const char *name, + int flags); /* * Internal logging API