[PATCH proxmox-backup-qemu v2 5/8] restore: implement `bw-limit` parameter imposing download rate limits

[Christian Ebner <c.ebner@proxmox.com>]

Add an optional `bw-limit` parameter to allow setting a download
bandwidth limit for pbs-restore. Since this is a breaking api change,
expose this in the public api as new function and refactor to keep
common code deduplicated.

Subsequently this new API function will be extend further by a
additional parameter.

Signed-off-by: Christian Ebner <c.ebner@proxmox.com>
---
 Cargo.toml     |  1 +
 current-api.h  | 13 +++++++++++++
 src/lib.rs     | 49 +++++++++++++++++++++++++++++++++++++++++++++++--
 src/restore.rs |  9 +++++++--
 4 files changed, 68 insertions(+), 4 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index d73324f..8b01ee0 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -32,6 +32,7 @@ once_cell = "1.5"
 openssl = "0.10"
 
 proxmox-async = "0.5"
+proxmox-human-byte = "1"
 proxmox-lang = "1"
 proxmox-schema = { version = "5", features = [ "api-macro" ] }
 proxmox-sortable-macro = "1"
diff --git a/current-api.h b/current-api.h
index 60d7558..b9a3a44 100644
--- a/current-api.h
+++ b/current-api.h
@@ -319,6 +319,19 @@ struct ProxmoxRestoreHandle *proxmox_restore_new_ns(const char *repo,
                                                     const char *fingerprint,
                                                     char **error);
 
+/**
+ * Connect to the backup server for restore (sync)
+ */
+struct ProxmoxRestoreHandle *proxmox_restore_new_ns_rate_limited(const char *repo,
+                                                                 const char *snapshot,
+                                                                 const char *namespace_,
+                                                                 const char *password,
+                                                                 const char *keyfile,
+                                                                 const char *key_password,
+                                                                 const char *fingerprint,
+                                                                 const char *bw_limit,
+                                                                 char **error);
+
 /**
  * Open connection to the backup server (sync)
  *
diff --git a/src/lib.rs b/src/lib.rs
index 1d4ea21..4d4c28b 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -3,12 +3,16 @@
 use anyhow::{format_err, Error};
 use std::ffi::CString;
 use std::os::raw::{c_char, c_int, c_long, c_uchar, c_void};
-use std::ptr;
+use std::ptr::{self, null};
 use std::sync::{Arc, Condvar, Mutex};
 
+use proxmox_human_byte::HumanByte;
 use proxmox_lang::try_block;
 
-use pbs_api_types::{Authid, BackupArchiveName, BackupDir, BackupNamespace, BackupType, CryptMode};
+use pbs_api_types::{
+    Authid, BackupArchiveName, BackupDir, BackupNamespace, BackupType, ClientRateLimitConfig,
+    CryptMode,
+};
 use pbs_client::BackupRepository;
 
 pub mod capi_types;
@@ -140,6 +144,7 @@ pub(crate) struct BackupSetup {
     pub key_password: Option<String>,
     pub master_keyfile: Option<std::path::PathBuf>,
     pub fingerprint: Option<String>,
+    pub inbound_rate_limit: Option<ClientRateLimitConfig>,
 }
 
 // helper class to implement synchronous interface
@@ -304,6 +309,7 @@ pub extern "C" fn proxmox_backup_new_ns(
             key_password,
             master_keyfile,
             fingerprint,
+            inbound_rate_limit: None,
         };
 
         BackupTask::new(setup, compress, crypt_mode)
@@ -816,6 +822,7 @@ pub extern "C" fn proxmox_restore_new(
             key_password,
             master_keyfile: None,
             fingerprint,
+            inbound_rate_limit: None,
         };
 
         RestoreTask::new(setup)
@@ -842,6 +849,33 @@ pub extern "C" fn proxmox_restore_new_ns(
     key_password: *const c_char,
     fingerprint: *const c_char,
     error: *mut *mut c_char,
+) -> *mut ProxmoxRestoreHandle {
+    proxmox_restore_new_ns_rate_limited(
+        repo,
+        snapshot,
+        namespace,
+        password,
+        keyfile,
+        key_password,
+        fingerprint,
+        null(),
+        error,
+    )
+}
+
+/// Connect to the backup server for restore (sync)
+#[no_mangle]
+#[allow(clippy::not_unsafe_ptr_arg_deref)]
+pub extern "C" fn proxmox_restore_new_ns_rate_limited(
+    repo: *const c_char,
+    snapshot: *const c_char,
+    namespace: *const c_char,
+    password: *const c_char,
+    keyfile: *const c_char,
+    key_password: *const c_char,
+    fingerprint: *const c_char,
+    bw_limit: *const c_char,
+    error: *mut *mut c_char,
 ) -> *mut ProxmoxRestoreHandle {
     let result: Result<_, Error> = try_block!({
         let repo: BackupRepository = tools::utf8_c_string(repo)?
@@ -862,6 +896,16 @@ pub extern "C" fn proxmox_restore_new_ns(
         let keyfile = tools::utf8_c_string(keyfile)?.map(std::path::PathBuf::from);
         let key_password = tools::utf8_c_string(key_password)?;
         let fingerprint = tools::utf8_c_string(fingerprint)?;
+        let inbound_rate_limit = match tools::utf8_c_string(bw_limit)? {
+            Some(rate_limit) => {
+                let rate_limit: HumanByte = rate_limit.parse()?;
+                Some(ClientRateLimitConfig {
+                    rate: Some(rate_limit),
+                    burst: None,
+                })
+            }
+            None => None,
+        };
 
         let setup = BackupSetup {
             host: repo.host().to_owned(),
@@ -876,6 +920,7 @@ pub extern "C" fn proxmox_restore_new_ns(
             key_password,
             master_keyfile: None,
             fingerprint,
+            inbound_rate_limit,
         };
 
         RestoreTask::new(setup)
diff --git a/src/restore.rs b/src/restore.rs
index 8f518bc..c6c1c9c 100644
--- a/src/restore.rs
+++ b/src/restore.rs
@@ -8,7 +8,7 @@ use tokio::runtime::Runtime;
 
 use proxmox_async::runtime::get_runtime_with_builder;
 
-use pbs_api_types::BackupArchiveName;
+use pbs_api_types::{BackupArchiveName, RateLimitConfig};
 use pbs_client::{BackupReader, HttpClient, HttpClientOptions, RemoteChunkReader};
 use pbs_datastore::cached_chunk_reader::CachedChunkReader;
 use pbs_datastore::data_blob::DataChunkBuilder;
@@ -91,11 +91,16 @@ impl RestoreTask {
     }
 
     pub async fn connect(&self) -> Result<libc::c_int, Error> {
-        let options = HttpClientOptions::new_non_interactive(
+        let mut options = HttpClientOptions::new_non_interactive(
             self.setup.password.clone(),
             self.setup.fingerprint.clone(),
         );
 
+        if let Some(limit) = self.setup.inbound_rate_limit.clone() {
+            let limit = RateLimitConfig::from_client_config(limit);
+            options = options.rate_limit(limit);
+        }
+
         let http = HttpClient::new(
             &self.setup.host,
             self.setup.port,
-- 
2.47.3