pass around config object

.gitignore

@@ -1,3 +1,4 @@
 /target
 /.idea
+/.vscode/settings.json
 **/*.rs.bk

.vscode/settings.json

@@ -1,3 +0,0 @@
-{
-    "editor.formatOnSave": true
-}

src/adapters/mod.rs

@@ -5,6 +5,7 @@ pub mod spawning;
 pub mod sqlite;
 pub mod tar;
 pub mod zip;
+use crate::preproc::PreprocConfig;
 use failure::*;
 use regex::{Regex, RegexSet};
 use std::io::prelude::*;
@@ -56,6 +57,7 @@ pub struct AdaptInfo<'a> {
     /// prefix every output line with this string to better indicate the file's location if it is in some archive
     pub line_prefix: &'a str,
     // pub adapt_subobject: &'a dyn Fn(AdaptInfo) -> Fallible<()>,
+    pub config: &'a mut PreprocConfig,
 }
 
 pub fn extension_to_regex(extension: &str) -> Regex {

src/adapters/tar.rs

@@ -58,6 +58,7 @@ impl FileAdapter for TarAdapter {
             oup,
             line_prefix,
             archive_recursion_depth,
+            config,
             ..
         } = ai;
 
@@ -81,8 +82,9 @@ impl FileAdapter for TarAdapter {
                     inp: &mut file,
                     oup,
                     line_prefix,
+                    config,
                 };
-                rga_preproc(ai2, None)?;
+                rga_preproc(ai2)?;
             }
         }
         Ok(())

src/adapters/zip.rs

@@ -50,6 +50,7 @@ impl FileAdapter for ZipAdapter {
             oup,
             line_prefix,
             archive_recursion_depth,
+            config,
             ..
         } = ai;
         loop {
@@ -67,17 +68,15 @@ impl FileAdapter for ZipAdapter {
                         file.compressed_size()
                     );
                     let line_prefix = &format!("{}{}: ", line_prefix, file.name());
-                    rga_preproc(
-                        AdaptInfo {
+                    rga_preproc(AdaptInfo {
                         filepath_hint: &file.sanitized_name(),
                         is_real_file: false,
                         inp: &mut file,
                         oup,
                         line_prefix,
-                            archive_recursion_depth,
-                        },
-                        None,
-                    )?;
+                        archive_recursion_depth: archive_recursion_depth + 1,
+                        config,
+                    })?;
                 }
                 Err(e) => return Err(e.into()),
             }

src/bin/rga-preproc.rs

@@ -17,6 +17,10 @@ fn main() -> Result<(), Error> {
 
     let i = File::open(&path)?;
     let mut o = std::io::stdout();
+    let cache = match env::var("RGA_NO_CACHE") {
+        Ok(ref s) if s.len() > 0 => None,
+        Ok(_) | Err(_) => Some(rga::preproc_cache::open()?),
+    };
     let ai = AdaptInfo {
         inp: &mut BufReader::new(i),
         filepath_hint: &path,
@@ -24,12 +28,8 @@ fn main() -> Result<(), Error> {
         oup: &mut o,
         line_prefix: "",
         archive_recursion_depth: 0,
+        config: &mut PreprocConfig { cache },
     };
 
-    let cache_db = match env::var("RGA_NO_CACHE") {
-        Ok(ref s) if s.len() > 0 => None,
-        Ok(_) | Err(_) => Some(open_cache_db()?),
-    };
-
-    rga_preproc(ai, cache_db)
+    rga_preproc(ai)
 }

src/caching_writer.rs

@@ -3,7 +3,8 @@ use std::io::Write;
 
 /**
  * wrap a writer so that it is passthrough,
- * but also the written data is compressed and written into a buffer, unless more than X bytes is written
+ * but also the written data is compressed and written into a buffer,
+ * unless more than max_cache_size bytes is written, then the cache is dropped and it is pure passthrough.
  */
 pub struct CachingWriter<W: Write> {
     max_cache_size: usize,

src/lib.rs

@@ -2,6 +2,6 @@
 
 pub mod adapters;
 mod caching_writer;
-pub mod errors;
 pub mod preproc;
+pub mod preproc_cache;
 pub use caching_writer::CachingWriter;

src/preproc.rs

@@ -1,47 +1,24 @@
 use crate::adapters::*;
 use crate::CachingWriter;
+use failure::Fallible;
 use failure::{format_err, Error};
 use path_clean::PathClean;
+use std::convert::AsRef;
 use std::io::BufWriter;
-
 // longest compressed conversion output to save in cache
 const MAX_DB_BLOB_LEN: usize = 2_000_000;
 const ZSTD_LEVEL: i32 = 12;
 
-/// opens a LMDB cache
-pub fn open_cache_db() -> Result<std::sync::Arc<std::sync::RwLock<rkv::Rkv>>, Error> {
-    let app_cache = cachedir::CacheDirConfig::new("rga").get_cache_dir()?;
-
-    let db_arc = rkv::Manager::singleton()
-        .write()
-        .expect("could not write db manager")
-        .get_or_create(app_cache.as_path(), |p| {
-            let mut builder = rkv::Rkv::environment_builder();
-            builder
-                .set_flags(rkv::EnvironmentFlags::NO_SYNC | rkv::EnvironmentFlags::WRITE_MAP) // not durable cuz it's a cache
-                // i'm not sure why NO_TLS is needed. otherwise LMDB transactions (open readers) will keep piling up until it fails with
-                // LmdbError(ReadersFull)
-                // hope it doesn't break integrity
-                .set_flags(rkv::EnvironmentFlags::NO_TLS)
-                .set_map_size(2 * 1024 * 1024 * 1024)
-                .set_max_dbs(100)
-                .set_max_readers(128);
-            rkv::Rkv::from_env(p, builder)
-        })
-        .expect("could not get/create db");
-    Ok(db_arc)
+pub struct PreprocConfig {
+    pub cache: Option<Box<dyn crate::preproc_cache::PreprocCache>>,
 }
-
 /**
  * preprocess a file as defined in `ai`.
  *
  * If a cache is passed, read/write to it.
  *
  */
-pub fn rga_preproc<'a>(
-    ai: AdaptInfo<'a>,
-    mb_db_arc: Option<std::sync::Arc<std::sync::RwLock<rkv::Rkv>>>,
-) -> Result<(), Error> {
+pub fn rga_preproc(ai: AdaptInfo) -> Result<(), Error> {
     let adapters = adapter_matcher()?;
     let AdaptInfo {
         filepath_hint,
@@ -49,6 +26,7 @@ pub fn rga_preproc<'a>(
         inp,
         oup,
         line_prefix,
+        config,
         ..
     } = ai;
     let filename = filepath_hint
@@ -71,10 +49,9 @@ pub fn rga_preproc<'a>(
             let meta = ad.metadata();
             eprintln!("adapter: {}", &meta.name);
             let db_name = format!("{}.v{}", meta.name, meta.version);
-            if let Some(db_arc) = mb_db_arc {
+            if let Some(cache) = config.cache.as_mut() {
                 let cache_key: Vec<u8> = {
                     let clean_path = filepath_hint.to_owned().clean();
-                    eprintln!("clean path: {:?}", clean_path);
                     let meta = std::fs::metadata(&filepath_hint)?;
 
                     let key = (
@@ -85,24 +62,10 @@ pub fn rga_preproc<'a>(
 
                     bincode::serialize(&key).expect("could not serialize path") // key in the cache database
                 };
-                let db_env = db_arc.read().unwrap();
-                let db = db_env
-                    .open_single(db_name.as_str(), rkv::store::Options::create())
-                    .map_err(|p| format_err!("could not open db store: {:?}", p))?;
-
-                let reader = db_env.read().expect("could not get reader");
-                let cached = db
-                    .get(&reader, &cache_key)
-                    .map_err(|p| format_err!("could not read from db: {:?}", p))?;
-                match cached {
-                    Some(rkv::Value::Blob(cached)) => {
-                        let stdouti = std::io::stdout();
-                        zstd::stream::copy_decode(cached, stdouti.lock())?;
-                        Ok(())
-                    }
-                    Some(_) => Err(format_err!("Integrity: value not blob")),
-                    None => {
-                        drop(reader);
+                cache.get_or_run(
+                    &db_name,
+                    &cache_key,
+                    Box::new(|| -> Fallible<Option<Vec<u8>>> {
                         // wrapping BufWriter here gives ~10% perf boost
                         let mut compbuf =
                             BufWriter::new(CachingWriter::new(oup, MAX_DB_BLOB_LEN, ZSTD_LEVEL)?);
@@ -114,6 +77,7 @@ pub fn rga_preproc<'a>(
                             inp,
                             oup: &mut compbuf,
                             archive_recursion_depth: 0,
+                            config: &mut PreprocConfig { cache: None },
                         })?;
                         let compressed = compbuf
                             .into_inner()
@@ -122,21 +86,16 @@ pub fn rga_preproc<'a>(
                             .finish()?;
                         if let Some(cached) = compressed {
                             eprintln!("compressed len: {}", cached.len());
-
-                            {
-                                let mut writer = db_env.write().map_err(|p| {
-                                    format_err!("could not open write handle to cache: {:?}", p)
-                                })?;
-                                db.put(&mut writer, &cache_key, &rkv::Value::Blob(&cached))
-                                    .map_err(|p| {
-                                        format_err!("could not write to cache: {:?}", p)
-                                    })?;
-                                writer.commit().unwrap();
-                            }
-                        }
+                        };
+                        Ok(None)
+                    }),
+                    Box::new(|cached| {
+                        let stdouti = std::io::stdout();
+                        zstd::stream::copy_decode(cached, stdouti.lock())?;
+                        Ok(())
+                    }),
+                )?;
                 Ok(())
-                    }
-                }
             } else {
                 eprintln!("adapting...");
                 ad.adapt(AdaptInfo {
@@ -146,6 +105,7 @@ pub fn rga_preproc<'a>(
                     inp,
                     oup,
                     archive_recursion_depth: 0,
+                    config: &mut PreprocConfig { cache: None },
                 })?;
                 Ok(())
             }

src/preproc_cache.rs

@@ -0,0 +1,90 @@
+use failure::{format_err, Fallible};
+
+pub fn open() -> Fallible<Box<dyn PreprocCache>> {
+    Ok(Box::new(LmdbCache::open()?))
+}
+pub trait PreprocCache {
+    // possible without second lambda?
+    fn get_or_run<'a>(
+        &mut self,
+        db_name: &str,
+        key: &[u8],
+        runner: Box<dyn FnOnce() -> Fallible<Option<Vec<u8>>> + 'a>,
+        callback: Box<dyn FnOnce(&[u8]) -> Fallible<()> + 'a>,
+    ) -> Fallible<()>;
+}
+
+/// opens a LMDB cache
+fn open_cache_db() -> Fallible<std::sync::Arc<std::sync::RwLock<rkv::Rkv>>> {
+    let app_cache = cachedir::CacheDirConfig::new("rga").get_cache_dir()?;
+
+    let db_arc = rkv::Manager::singleton()
+        .write()
+        .expect("could not write db manager")
+        .get_or_create(app_cache.as_path(), |p| {
+            let mut builder = rkv::Rkv::environment_builder();
+            builder
+                .set_flags(rkv::EnvironmentFlags::NO_SYNC | rkv::EnvironmentFlags::WRITE_MAP) // not durable cuz it's a cache
+                // i'm not sure why NO_TLS is needed. otherwise LMDB transactions (open readers) will keep piling up until it fails with
+                // LmdbError(ReadersFull)
+                // hope it doesn't break integrity
+                .set_flags(rkv::EnvironmentFlags::NO_TLS)
+                .set_map_size(2 * 1024 * 1024 * 1024)
+                .set_max_dbs(100)
+                .set_max_readers(128);
+            rkv::Rkv::from_env(p, builder)
+        })
+        .expect("could not get/create db");
+    Ok(db_arc)
+}
+
+pub struct LmdbCache {
+    db_arc: std::sync::Arc<std::sync::RwLock<rkv::Rkv>>,
+}
+
+impl LmdbCache {
+    pub fn open() -> Fallible<LmdbCache> {
+        Ok(LmdbCache {
+            db_arc: open_cache_db()?,
+        })
+    }
+}
+impl PreprocCache for LmdbCache {
+    // possible without second lambda?
+    fn get_or_run<'a>(
+        &mut self,
+        db_name: &str,
+        key: &[u8],
+        runner: Box<dyn FnOnce() -> Fallible<Option<Vec<u8>>> + 'a>,
+        callback: Box<dyn FnOnce(&[u8]) -> Fallible<()> + 'a>,
+    ) -> Fallible<()> {
+        let db_env = self.db_arc.read().unwrap();
+        let db = db_env
+            .open_single(db_name, rkv::store::Options::create())
+            .map_err(|p| format_err!("could not open db store: {:?}", p))?;
+
+        let reader = db_env.read().expect("could not get reader");
+        let cached = db
+            .get(&reader, &key)
+            .map_err(|p| format_err!("could not read from db: {:?}", p))?;
+
+        match cached {
+            Some(rkv::Value::Blob(cached)) => {
+                callback(cached)?;
+            }
+            Some(_) => Err(format_err!("Integrity: value not blob"))?,
+            None => {
+                drop(reader);
+                if let Some(got) = runner()? {
+                    let mut writer = db_env.write().map_err(|p| {
+                        format_err!("could not open write handle to cache: {:?}", p)
+                    })?;
+                    db.put(&mut writer, &key, &rkv::Value::Blob(&got))
+                        .map_err(|p| format_err!("could not write to cache: {:?}", p))?;
+                    writer.commit()?;
+                }
+            }
+        };
+        Ok(())
+    }
+}