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| author | Calvin Wan <calvinwan@google.com> | 2025-01-29 13:50:44 -0800 |
|---|---|---|
| committer | Junio C Hamano <gitster@pobox.com> | 2025-01-29 15:06:50 -0800 |
| commit | 65c10aa8d5000e0ecab34a9652056f0520fe51ed (patch) | |
| tree | 20cf8b5a947d7eff531b68a08af0a26691e68916 /contrib/libgit-rs/src/config.rs | |
| parent | d76eb0dcccb19d2f85924a4be177ae76126bf5d3 (diff) | |
| download | git-65c10aa8d5000e0ecab34a9652056f0520fe51ed.tar.gz | |
libgit: add higher-level libgit crate
The C functions exported by libgit-sys do not provide an idiomatic Rust
interface. To make it easier to use these functions via Rust, add a
higher-level "libgit" crate, that wraps the lower-level configset API
with an interface that is more Rust-y.
This combination of $X and $X-sys crates is a common pattern for FFI in
Rust, as documented in "The Cargo Book" [1].
[1] https://doc.rust-lang.org/cargo/reference/build-scripts.html#-sys-packages
Co-authored-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Calvin Wan <calvinwan@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'contrib/libgit-rs/src/config.rs')
| -rw-r--r-- | contrib/libgit-rs/src/config.rs | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/contrib/libgit-rs/src/config.rs b/contrib/libgit-rs/src/config.rs new file mode 100644 index 0000000000..6bf04845c8 --- /dev/null +++ b/contrib/libgit-rs/src/config.rs @@ -0,0 +1,106 @@ +use std::ffi::{c_void, CStr, CString}; +use std::path::Path; + +#[cfg(has_std__ffi__c_char)] +use std::ffi::{c_char, c_int}; + +#[cfg(not(has_std__ffi__c_char))] +#[allow(non_camel_case_types)] +type c_char = i8; + +#[cfg(not(has_std__ffi__c_char))] +#[allow(non_camel_case_types)] +type c_int = i32; + +use libgit_sys::*; + +/// A ConfigSet is an in-memory cache for config-like files such as `.gitmodules` or `.gitconfig`. +/// It does not support all config directives; notably, it will not process `include` or +/// `includeIf` directives (but it will store them so that callers can choose whether and how to +/// handle them). +pub struct ConfigSet(*mut libgit_config_set); +impl ConfigSet { + /// Allocate a new ConfigSet + pub fn new() -> Self { + unsafe { ConfigSet(libgit_configset_alloc()) } + } + + /// Load the given files into the ConfigSet; conflicting directives in later files will + /// override those given in earlier files. + pub fn add_files(&mut self, files: &[&Path]) { + for file in files { + let pstr = file.to_str().expect("Invalid UTF-8"); + let rs = CString::new(pstr).expect("Couldn't convert to CString"); + unsafe { + libgit_configset_add_file(self.0, rs.as_ptr()); + } + } + } + + /// Load the value for the given key and attempt to parse it as an i32. Dies with a fatal error + /// if the value cannot be parsed. Returns None if the key is not present. + pub fn get_int(&mut self, key: &str) -> Option<i32> { + let key = CString::new(key).expect("Couldn't convert to CString"); + let mut val: c_int = 0; + unsafe { + if libgit_configset_get_int(self.0, key.as_ptr(), &mut val as *mut c_int) != 0 { + return None; + } + } + + Some(val.into()) + } + + /// Clones the value for the given key. Dies with a fatal error if the value cannot be + /// converted to a String. Returns None if the key is not present. + pub fn get_string(&mut self, key: &str) -> Option<String> { + let key = CString::new(key).expect("Couldn't convert key to CString"); + let mut val: *mut c_char = std::ptr::null_mut(); + unsafe { + if libgit_configset_get_string(self.0, key.as_ptr(), &mut val as *mut *mut c_char) != 0 + { + return None; + } + let borrowed_str = CStr::from_ptr(val); + let owned_str = + String::from(borrowed_str.to_str().expect("Couldn't convert val to str")); + free(val as *mut c_void); // Free the xstrdup()ed pointer from the C side + Some(owned_str) + } + } +} + +impl Default for ConfigSet { + fn default() -> Self { + Self::new() + } +} + +impl Drop for ConfigSet { + fn drop(&mut self) { + unsafe { + libgit_configset_free(self.0); + } + } +} + +#[cfg(test)] +mod tests { + use super::*; + + #[test] + fn load_configs_via_configset() { + let mut cs = ConfigSet::new(); + cs.add_files(&[ + Path::new("testdata/config1"), + Path::new("testdata/config2"), + Path::new("testdata/config3"), + ]); + // ConfigSet retrieves correct value + assert_eq!(cs.get_int("trace2.eventTarget"), Some(1)); + // ConfigSet respects last config value set + assert_eq!(cs.get_int("trace2.eventNesting"), Some(3)); + // ConfigSet returns None for missing key + assert_eq!(cs.get_string("foo.bar"), None); + } +} |