1 files changed, 127 insertions, 0 deletions
diff --git a/libsyslog/src/builder.rs b/libsyslog/src/builder.rs
new file mode 100644
index 0000000..c4b0781
--- /dev/null
+++ b/libsyslog/src/builder.rs
@@ -0,0 +1,127 @@
+use {
+    crate::{
+        Facility,
+        Syslog,
+    },
+
+    libsyslog_sys::*,
+    log::{
+        LevelFilter,
+    },
+    std::{
+        env::args,
+        ffi::{
+            CString,
+            NulError,
+        },
+        os::raw::c_int,
+    },
+};
+
+#[cfg(feature = "bitflags")]
+use crate::Logopt;
+
+/// Builder used to create and customize the [Syslog][Syslog] logger object.
+#[derive(Debug,Default)]
+pub struct SyslogBuilder {
+    facility_opt: Option<c_int>,
+    ident_opt: Option<CString>,
+    level_opt: Option<LevelFilter>,
+    logopt_opt: Option<c_int>,
+    module_levels: Vec<(String, LevelFilter)>,
+}
+
+impl SyslogBuilder {
+    fn ident_from_argv() -> CString {
+        let argv0 = args().next().unwrap_or_default();
+        let program = match argv0.rsplit_once('/') {
+            Some((_, filename)) => filename,
+            None => argv0.as_str(),
+        };
+        CString::new(program).unwrap_or_default()
+    }
+
+    #[must_use = "Syslog only gets active after calling .init() on it."]
+    pub fn build(self) -> Syslog {
+    //! Consumes `self` and returns a freshly created [`Syslog`] logger object. To be called at
+    //! the end of the builder chain, after all other methods on the [`SyslogBuilder`] object.
+
+        let facility = self.facility_opt.unwrap_or(Facility::default() as c_int);
+        let ident = self.ident_opt.unwrap_or_else(Self::ident_from_argv);
+        let level = self.level_opt.unwrap_or(LevelFilter::Info);
+        let logopt = self.logopt_opt.unwrap_or(LOG_PID);
+        let module_levels = self.module_levels;
+
+        Syslog {
+            facility,
+            ident,
+            level,
+            logopt,
+            module_levels,
+        }
+    }
+
+    #[must_use = "No Syslog is constructed unless .build() is called."]
+    pub fn facility(mut self, facility: Facility) -> Self {
+    //! Sets logging facility to given [`Facility`] value.
+
+        self.facility_opt = Some(facility as c_int);
+        self
+    }
+
+    #[must_use = "No Syslog is constructed unless .build() is called."]
+    pub fn facility_raw(mut self, facility: c_int) -> Self {
+    //! Sets logging facility to unchecked `c_int` value. Can be used for
+    //! setting a raw [libsyslog-sys][libsyslog_sys] constant directly.
+
+        self.facility_opt = Some(facility);
+        self
+    }
+
+    #[must_use = "No Syslog is constructed unless .build() is called."]
+    pub fn ident<T: Into<Vec<u8>>>(mut self, ident: T) -> Result<Self, NulError> {
+    //! Sets ident to the string like argument provided. By default ident is
+    //! derived from the name of the executable.
+
+        self.ident_opt = Some(CString::new(ident)?);
+        Ok(self)
+    }
+
+    #[must_use = "No Syslog is constructed unless .build() is called."]
+    pub fn level(mut self, level: LevelFilter) -> Self {
+    //! Sets global log level to be used when no
+    //! [module_level][`SyslogBuilder::module_level`] rule matches.
+
+        self.level_opt = Some(level);
+        self
+    }
+
+    #[cfg(feature = "bitflags")]
+    #[must_use = "No Syslog is constructed unless .build() is called."]
+    pub fn logopt(mut self, logopt: Logopt) -> Self {
+    //! Sets logopt to to given [`Logopt`] value.
+
+        self.logopt_opt = Some(logopt.bits());
+        self
+    }
+
+    #[must_use = "No Syslog is constructed unless .build() is called."]
+    pub fn logopt_raw(mut self, logopt: c_int) -> Self {
+    //! Sets logopt to unchecked `c_int` value. Can be used for setting a raw
+    //! [libsyslog-sys][libsyslog_sys] constant directly.
+
+        self.logopt_opt = Some(logopt);
+        self
+    }
+
+    #[must_use = "No Syslog is constructed unless .build() is called."]
+    pub fn module_level(mut self, target: &str, level: LevelFilter) -> Self {
+    //! Sets log level for specified target Rust module. Multiple calls to this
+    //! method is possible and will set multiple filters. More specific filters
+    //! on children will override those of their parent modules.
+
+        self.module_levels.push((target.to_string(), level));
+        self
+    }
+}
+