Feature-gate consistency check

This brings down compile times by two seconds on my local machine.

Author: jyn514

Cargo.toml

@@ -15,11 +15,14 @@ exclude = [
     ".rustwide-docker",
 ]
 
+[features]
+consistency_check = ["crates-index"]
+
 [dependencies]
 log = "0.4"
 regex = "1"
 structopt = "0.3"
-crates-index = "0.15.1"
+crates-index = { version = "0.15.1", optional = true }
 crates-index-diff = "7.1.1"
 reqwest = { version = "0.10.6", features = ["blocking", "json"] } # TODO: Remove blocking when async is ready
 semver = { version = "0.9", features = ["serde"] }

src/bin/cratesfyi.rs

@@ -404,6 +404,7 @@ enum DatabaseSubcommand {
     },
 
     /// Compares the database with the index and resolves inconsistencies
+    #[cfg(feature = "consistency_check")]
     Synchronize {
         /// Don't actually resolve the inconsistencies, just log them
         #[structopt(long)]
@@ -455,6 +456,7 @@ impl DatabaseSubcommand {
                 .context("failed to delete the crate")?,
             Self::Blacklist { command } => command.handle_args(ctx)?,
 
+            #[cfg(feature = "consistency_check")]
             Self::Synchronize { dry_run } => {
                 docs_rs::utils::consistency::run_check(&mut *ctx.conn()?, &*ctx.index()?, dry_run)?;
             }

src/index/mod.rs

@@ -2,11 +2,12 @@ use std::{path::PathBuf, process::Command};
 
 use url::Url;
 
-use self::{api::Api, crates::Crates};
+use self::api::Api;
 use crate::error::Result;
 use failure::ResultExt;
 
 pub(crate) mod api;
+#[cfg(feature = "consistency_check")]
 mod crates;
 
 pub struct Index {
@@ -83,15 +84,16 @@ impl Index {
         Ok(diff)
     }
 
-    pub(crate) fn crates(&self) -> Result<Crates> {
+    #[cfg(feature = "consistency_check")]
+    pub(crate) fn crates(&self) -> Result<crates::Crates> {
         // First ensure the index is up to date, peeking will pull the latest changes without
         // affecting anything else.
         log::debug!("Updating index");
         self.diff()?.peek_changes()?;
         // It'd be nice to use `crates_index` directly for interacting with the index, but it
         // doesn't support bare repositories. So we use its `Crate` type but walk the index
         // ourselves.
-        Ok(Crates::new(git2::Repository::open(&self.path)?))
+        Ok(crates::Crates::new(git2::Repository::open(&self.path)?))
     }
 
     pub fn api(&self) -> &Api {

src/utils/mod.rs

@@ -14,6 +14,7 @@ pub(crate) use self::rustc_version::parse_rustc_version;
 pub(crate) use self::cargo_metadata::{Dependency, Target};
 
 mod cargo_metadata;
+#[cfg(feature = "consistency_check")]
 pub mod consistency;
 mod copy;
 mod daemon;