From 846f4775d93868737de44edd4510af91351f930d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sebastian=20Dr=C3=B6ge?= <sebastian@centricular.com>
Date: Sun, 15 May 2016 11:48:54 +0300
Subject: [PATCH] Implement seeking in HTTP source

---
 src/rshttpsrc.rs | 128 ++++++++++++++++++++++++++++++++++-------------
 1 file changed, 92 insertions(+), 36 deletions(-)

diff --git a/src/rshttpsrc.rs b/src/rshttpsrc.rs
index 27bca6cd..3b2add3d 100644
--- a/src/rshttpsrc.rs
+++ b/src/rshttpsrc.rs
@@ -1,7 +1,7 @@
 use std::u64;
 use std::io::{Read, Seek, SeekFrom};
 use url::Url;
-use hyper::header::ContentLength;
+use hyper::header::{ContentLength, ContentRange, ContentRangeSpec, Range, ByteRangeSpec, AcceptRanges, RangeUnit};
 use hyper::client::Client;
 use hyper::client::response::Response;
 
@@ -15,13 +15,16 @@ pub struct HttpSrc {
     url: Option<Url>,
     client: Client,
     response: Option<Response>,
+    seekable: bool,
     position: u64,
     size: u64,
+    start: u64,
+    stop: u64,
 }
 
 impl HttpSrc {
     fn new() -> HttpSrc {
-        HttpSrc { url: None, client: Client::new(), response: None, position: 0, size: u64::MAX }
+        HttpSrc { url: None, client: Client::new(), response: None, seekable: false, position: 0, size: u64::MAX, start: 0, stop: u64::MAX }
     }
 
     fn new_source() -> Box<Source> {
@@ -31,10 +34,81 @@ impl HttpSrc {
         let instance = Box::new(HttpSrc::new_source());
         return Box::into_raw(instance);
     }
+
+    pub fn do_request(&mut self, start: u64, stop: u64) -> bool {
+        self.response = None;
+        self.seekable = false;
+        self.position = 0;
+        self.size = u64::MAX;
+
+        match self.url {
+            None => return false,
+            Some(ref url) => {
+                let mut req = self.client.get(url.clone());
+
+                if start != 0 || stop != u64::MAX {
+                    req = if stop == u64::MAX {
+                            req.header(Range::Bytes(vec![ByteRangeSpec::AllFrom(start)]))
+                        } else {
+                            req.header(Range::Bytes(vec![ByteRangeSpec::FromTo(start, stop)]))
+                        };
+                }
+
+                match req.send() {
+                    Ok(response) => {
+                        if response.status.is_success() {
+                            self.size = if let Some(&ContentLength(content_length)) = response.headers.get() {
+                                content_length + start
+                            } else {
+                                u64::MAX
+                            };
+                            let accept_byte_ranges = if let Some(&AcceptRanges(ref ranges)) = response.headers.get() {
+                                ranges.iter().any(|u| *u == RangeUnit::Bytes)
+                            } else {
+                                false
+                            };
+
+                            self.seekable = self.size != u64::MAX && accept_byte_ranges;
+
+                            self.start = start;
+                            self.stop = stop;
+
+                            self.position = if let Some(&ContentRange(ContentRangeSpec::Bytes{range: Some((range_start, _)), ..})) = response.headers.get() {
+                                range_start
+                            } else {
+                                start
+                            };
+
+                            if self.position != start {
+                                println_err!("Failed to seek to {}: Got {}", start, self.position);
+                                return false;
+                            }
+
+                            self.response = Some(response);
+
+                            return true;
+                        } else {
+                            println_err!("Failed to fetch {}: {}", url, response.status);
+                            return false;
+                        }
+                    },
+                    Err(err) => {
+                        println_err!("Failed to fetch {}: {}", url, err.to_string());
+                        return false;
+                    }
+                }
+            },
+        }
+    }
 }
 
 impl Source for HttpSrc {
     fn set_uri(&mut self, uri_str: &Option<String>) -> bool {
+        if self.response.is_some() {
+            println_err!("Can't set URI after starting");
+            return false;
+        }
+
         match *uri_str {
             None => {
                 self.url = None;
@@ -69,7 +143,7 @@ impl Source for HttpSrc {
     }
 
     fn is_seekable(&self) -> bool {
-        false
+        self.seekable
     }
 
     fn get_size(&self) -> u64 {
@@ -77,37 +151,12 @@ impl Source for HttpSrc {
     }
 
     fn start(&mut self) -> bool {
-        self.response = None;
-        self.position = 0;
-        self.size = u64::MAX;
-
-        match self.url {
-            None => return false,
-            Some(ref url) => {
-                match self.client.get(url.clone()).send() {
-                    Ok(response) => {
-                        if response.status.is_success() {
-                            self.size = match response.headers.get::<ContentLength>() {
-                                Some(&ContentLength(size)) => size,
-                                _ => u64::MAX
-                            };
-                            self.response = Some(response);
-                            return true;
-                        } else {
-                            println_err!("Failed to fetch {}: {}", url, response.status);
-                            return false;
-                        }
-                    },
-                    Err(err) => {
-                        println_err!("Failed to fetch {}: {}", url, err.to_string());
-                        return false;
-                    }
-                }
-            },
-        }
+        self.seekable = false;
+        return self.do_request(0, u64::MAX);
     }
 
     fn stop(&mut self) -> bool {
+        self.seekable = false;
         self.position = 0;
         self.size = u64::MAX;
         match self.response {
@@ -119,15 +168,22 @@ impl Source for HttpSrc {
         return true;
     }
 
+    fn do_seek(&mut self, start: u64, stop: u64) -> bool {
+        return self.do_request(start, stop);
+    }
+
     fn fill(&mut self, offset: u64, data: &mut [u8]) -> Result<usize, GstFlowReturn> {
+        if self.position != offset || self.response.is_none() {
+            let stop = self.stop;
+            if !self.do_request(offset, stop) {
+                println_err!("Failed to seek to {}", offset);
+                return Err(GstFlowReturn::Error);
+            }
+        }
+
         match self.response {
             None => return Err(GstFlowReturn::Error),
             Some(ref mut r) => {
-                if self.position != offset {
-                       println_err!("Failed to seek to {}", offset);
-                       return Err(GstFlowReturn::Error);
-                }
-
                 match r.read(data) {
                     Ok(size) => {
                         if size == 0 {