Merge pull request #28 from iqlusion-io/rpmlib-simplification

Simplify API by eliminating `Database` and hiding `TransactionSet`

Author: tarcieri

Cargo.lock

@@ -19,4 +19,3 @@ failure = "0.1"
 lazy_static = "1"
 libc = { version = "0.2", default-features = false }
 rpmlib-sys = { version = "0.4", path = "../rpmlib-sys" }
-streaming-iterator = "0.1"

rpmlib/Cargo.toml

@@ -1,274 +1,54 @@
-//! RPM database binding
-
-use failure::Error;
-use libc;
-use rpmlib_sys::rpmlib;
-use std::ffi::CString;
-use std::ptr;
-use streaming_iterator::StreamingIterator;
-
-use header::Header;
-use tag::Tag;
-use ts::TransactionSet;
-
-/// RPM database access: this type provides a handle to an RPM database valid
-/// for the lifetime of a transaction.
-///
-/// The database used is whichever one is configured as the `_dbpath` in the
-/// in the global macro context. By default this is unset: you will need to
-/// call `rpmlib::read_config(None)` to read the default "rpmrc" configuration.
-///
-/// # Example
-///
-/// Finding the "rpm-devel" RPM in the database:
-///
-/// ```
-/// use rpmlib::{self, Database, StreamingIterator, Txn, Tag, TagData};
-///
-/// rpmlib::config::read_file(None).unwrap();
-///
-/// let mut txn = Txn::create().unwrap();
-/// let mut db = Database::open(&mut txn, false).unwrap();
-/// let mut matches = db.find(Tag::NAME, "rpm-devel");
-/// let package = matches.next().unwrap();
-///
-/// match package.get(Tag::NAME) {
-///     TagData::Str(ref s) => println!("package name: {}", s),
-///     _ => ()
-/// }
-///
-/// match package.get(Tag::DESCRIPTION) {
-///     TagData::Str(ref s) => println!("package description: {}", s),
-///     _ => ()
-/// }
-/// ```
-pub struct Database<'ts> {
-    /// Borrows the `TransactionSet` mutably so we can control its database
-    ts: &'ts mut TransactionSet,
-}
-
-impl<'ts> Database<'ts> {
-    /// Open the default database
-    pub fn open(ts: &'ts mut TransactionSet, writable: bool) -> Result<Self, Error> {
-        let dbmode = if writable {
-            libc::O_RDWR
-        } else {
-            libc::O_RDONLY
-        };
-
-        let ts_ptr = ts.as_ptr();
-        if unsafe { ts.ffi().rpmtsOpenDB(ts_ptr, dbmode) } != 0 {
-            // TODO: check the _dbpath macro and see if it's set?
-            bail!("couldn't open _dbpath (writable: {})!", writable);
-        }
-
-        Ok(Self { ts })
-    }
-
-    /// Return an iterator over all of the packages in the database.
-    pub fn packages<'db>(&'db mut self) -> MatchIterator<'db, 'ts> {
-        let ts_ptr = self.ts.as_ptr();
-        let iter_ptr = unsafe {
-            self.ts
-                .ffi()
-                .rpmtsInitIterator(ts_ptr, rpmlib::rpmTag_e_RPMTAG_NAME, ptr::null(), 0)
-        };
-
-        MatchIterator::new(self, iter_ptr)
-    }
-
-    /// Find packages with a search key that exatcly matches the given tag.
-    ///
-    /// Panics if the glob contains null bytes.
-    #[inline]
-    pub fn find<'db, K>(&'db mut self, tag: Tag, key: K) -> MatchIterator<'db, 'ts>
-    where
-        K: AsRef<str>,
-    {
-        let mut iter = self.packages();
-        iter.find(tag, key);
-        iter
-    }
-
-    /// Find all packages with the given tag that match the given "glob"
-    ///
-    /// Panics if the glob contains null bytes.
-    #[inline]
-    pub fn find_glob<'db, G>(&'db mut self, tag: Tag, glob: &G) -> MatchIterator<'db, 'ts>
-    where
-        G: AsRef<str>,
-    {
-        let mut iter = self.packages();
-        iter.glob(tag, glob);
-        iter
-    }
-
-    /// Find all packages with the given tag that match the given regex
-    ///
-    /// Panics if the regex contains null bytes.
-    #[inline]
-    pub fn find_regex<'db, R>(&'db mut self, tag: Tag, regex: &R) -> MatchIterator<'db, 'ts>
-    where
-        R: AsRef<str>,
-    {
-        let mut iter = self.packages();
-        iter.regex(tag, regex);
-        iter
-    }
-
-    /// Obtain the TransactionSet this database was opened under
-    #[inline]
-    pub fn transaction_set(&mut self) -> &mut TransactionSet {
-        &mut self.ts
-    }
-}
-
-impl<'ts> Drop for Database<'ts> {
-    fn drop(&mut self) {
-        unsafe {
-            let ts_ptr = self.ts.as_ptr();
-            self.ts.ffi().rpmtsCloseDB(ts_ptr);
-        }
-    }
-}
-
-/// Iterator over the matches from a database query
-pub struct MatchIterator<'db, 'ts: 'db> {
-    // TODO: allow Header to borrow mut borrow the database for a safer memory
-    // model. See notes in `header.rs`
-    #[allow(dead_code)]
-    db: &'db mut Database<'ts>,
-    ptr: rpmlib::rpmdbMatchIterator,
-    next_item: Option<Header>,
-}
-
-impl<'db, 'ts> MatchIterator<'db, 'ts> {
-    pub(crate) fn new(db: &'db mut Database<'ts>, ptr: rpmlib::rpmdbMatchIterator) -> Self {
-        assert!(!ptr.is_null(), "iterator pointer is NULL!");
-        Self {
-            db,
-            ptr,
-            next_item: None,
-        }
-    }
-
-    /// Find packages with a search key that exatcly matches the given tag.
-    ///
-    /// Panics if the glob contains null bytes.
-    pub fn find<K>(&mut self, tag: Tag, key: K) -> &mut Self
-    where
-        K: AsRef<str>,
-    {
-        let key_cstr = CString::new(key.as_ref()).unwrap();
-
-        unsafe {
-            self.db.ts.ffi().rpmdbSetIteratorRE(
-                self.ptr,
-                tag as rpmlib::rpm_tag_t,
-                rpmlib::rpmMireMode_e_RPMMIRE_STRCMP,
-                key_cstr.as_ptr(),
-            );
-        }
-
-        self
-    }
-
-    /// Find all packages with the given tag that match the given "glob"
-    ///
-    /// Panics if the glob contains null bytes.
-    pub fn glob<G>(&mut self, tag: Tag, glob: &G) -> &mut Self
-    where
-        G: AsRef<str>,
-    {
-        let glob_cstr = CString::new(glob.as_ref()).unwrap();
-
-        unsafe {
-            self.db.ts.ffi().rpmdbSetIteratorRE(
-                self.ptr,
-                tag as rpmlib::rpm_tag_t,
-                rpmlib::rpmMireMode_e_RPMMIRE_GLOB,
-                glob_cstr.as_ptr(),
-            );
-        }
-
-        self
-    }
-
-    /// Find all packages with the given tag that match the given regex
-    ///
-    /// Panics if the regex contains null bytes.
-    pub fn regex<R>(&mut self, tag: Tag, regex: &R) -> &mut Self
-    where
-        R: AsRef<str>,
-    {
-        let regex_cstr = CString::new(regex.as_ref()).unwrap();
-
-        unsafe {
-            self.db.ts.ffi().rpmdbSetIteratorRE(
-                self.ptr,
-                tag as rpmlib::rpm_tag_t,
-                rpmlib::rpmMireMode_e_RPMMIRE_REGEX,
-                regex_cstr.as_ptr(),
-            );
-        }
-
-        self
-    }
-}
-
-impl<'db, 'ts> StreamingIterator for MatchIterator<'db, 'ts> {
-    type Item = Header;
-
-    fn advance(&mut self) {
-        let header_ptr = unsafe { self.db.ts.ffi().rpmdbNextIterator(self.ptr) };
-
-        if header_ptr.is_null() {
-            self.next_item = None
-        } else {
-            self.next_item = Some(Header::new(header_ptr))
-        }
-    }
-
-    fn get(&self) -> Option<&Header> {
-        self.next_item.as_ref()
-    }
-}
-
-impl<'db, 'ts> Drop for MatchIterator<'db, 'ts> {
-    fn drop(&mut self) {
-        unsafe {
-            self.db.ts.ffi().rpmdbFreeIterator(self.ptr);
-        }
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use {config, Database, Tag, TagData, Txn};
-    use streaming_iterator::StreamingIterator;
-
-    /// The `.rpm` containing rpmlib itself
-    const TEST_PACKAGE: &str = "rpm-devel";
-
-    #[test]
-    fn test_package_lookup() {
-        // Read the default config
-        // TODO: create a mock RPM database for testing
-        config::read_file(None).unwrap();
-
-        let mut txn = Txn::create().unwrap();
-        let mut db = Database::open(&mut txn, false).unwrap();
-        let mut matches = db.find(Tag::NAME, TEST_PACKAGE);
-
-        if let Some(package) = matches.next() {
-            match package.get(Tag::NAME) {
-                TagData::Str(ref s) => assert_eq!(s, &TEST_PACKAGE),
-                _ => panic!("unexpected result for package.get()!"),
-            }
-        } else {
-            panic!("expected 1 result, got 0!");
-        }
-
-        assert!(matches.next().is_none(), "expected one result, got more!");
-    }
+//! RPM database access
+//!
+//! The database used is whichever one is configured as the `_dbpath` in the
+//! in the global macro context. By default this is unset: you will need to
+//! call `rpmlib::config::read_file(None)` to read the default "rpmrc"
+//! configuration.
+//!
+//! # Example
+//!
+//! Finding the "rpm-devel" RPM in the database:
+//!
+//! ```
+//! use rpmlib::{self, Tag};
+//!
+//! rpmlib::config::read_file(None).unwrap();
+//!
+//! let mut matches = rpmlib::db::find(Tag::NAME, "rpm-devel");
+//! let headers = matches.next().unwrap();
+//!
+//! println!("package name: {}", headers.name());
+//! println!("package description: {}", headers.description());
+//! ```
+
+use {MatchIterator, Tag};
+
+/// Find all packages in the RPM database
+pub fn all_packages() -> MatchIterator {
+    MatchIterator::new(Tag::NAME, None)
+}
+
+/// Find packages with a search key that exactly matches the given tag.
+///
+/// Panics if the glob contains null bytes.
+pub fn find(tag: Tag, key: &str) -> MatchIterator {
+    MatchIterator::new(tag, Some(key))
+}
+
+/// Find all packages with the given tag that match the given "glob"
+///
+/// Panics if the glob contains null bytes.
+pub fn glob(tag: Tag, glob: &str) -> MatchIterator {
+    let mut iter = all_packages();
+    iter.glob(tag, glob);
+    iter
+}
+
+/// Find all packages with the given tag that match the given regex
+///
+/// Panics if the regex contains null bytes.
+pub fn regex(tag: Tag, regex: &str) -> MatchIterator {
+    let mut iter = all_packages();
+    iter.regex(tag, regex);
+    iter
 }