From 3904afa1ff696c64e13cf4c9c2b0b355bab8ec36 Mon Sep 17 00:00:00 2001
From: Tianhao Chai <cth451@gmail.com>
Date: Sat, 21 Aug 2021 21:46:35 -0500
Subject: [PATCH] file abstraction: actually follow lseek semantics

Signed-off-by: Tianhao Chai <cth451@aosc.io>
(cherry picked from commit 0b60970d5a332a2af569f26fd3b8fb5cff34e036)
---
 akode/lib/file.h        | 2 +-
 akode/lib/localfile.cpp | 8 ++++----
 akode/lib/localfile.h   | 2 +-
 akode/lib/mmapfile.cpp  | 8 ++++----
 akode/lib/mmapfile.h    | 2 +-
 5 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/akode/lib/file.h b/akode/lib/file.h
index 11a4fef..3685bcc 100644
--- a/akode/lib/file.h
+++ b/akode/lib/file.h
@@ -76,7 +76,7 @@ public:
     * Seeks to the position.
     * Behaves semantically as lseek.
     */
-    virtual bool seek(long to, int whence = SEEK_SET) = 0;
+    virtual ssize_t seek(long to, int whence = SEEK_SET) = 0;
    /*!
     * Returns current position in file, or negative if unknown.
     */
diff --git a/akode/lib/localfile.cpp b/akode/lib/localfile.cpp
index ff92760..35ce2f3 100644
--- a/akode/lib/localfile.cpp
+++ b/akode/lib/localfile.cpp
@@ -115,11 +115,11 @@ long LocalFile::write(const char* ptr, long num) {
     return n;
 }
 
-bool LocalFile::seek(long to, int whence) {
-    if(_fd == -1) return false;
-    int s = ::lseek(_fd, to, whence);
+ssize_t LocalFile::seek(long to, int whence) {
+    if(_fd == -1) return -1;
+    ssize_t s = ::lseek(_fd, to, whence);
     if (s >= 0) pos = s;
-    return (s >= 0);
+    return s;
 }
 
 long LocalFile::position() const {
diff --git a/akode/lib/localfile.h b/akode/lib/localfile.h
index 7f7c2c2..9003e43 100644
--- a/akode/lib/localfile.h
+++ b/akode/lib/localfile.h
@@ -50,7 +50,7 @@ public:
     long read(char* ptr, long num);
     long write(const char* ptr, long num);
 
-    bool seek(long to, int whence = SEEK_SET);
+    ssize_t seek(long to, int whence = SEEK_SET);
     long position() const;
     long length() const;
 
diff --git a/akode/lib/mmapfile.cpp b/akode/lib/mmapfile.cpp
index 4c45603..ec45f98 100644
--- a/akode/lib/mmapfile.cpp
+++ b/akode/lib/mmapfile.cpp
@@ -94,7 +94,7 @@ long MMapFile::write(const char*, long) {
     return false;
 }
 
-bool MMapFile::seek(long to, int whence) {
+ssize_t MMapFile::seek(long to, int whence) {
     if(!handle) return false;
 
     long newpos = 0;
@@ -109,12 +109,12 @@ bool MMapFile::seek(long to, int whence) {
             newpos = len + to;
             break;
         default:
-            return false;
+            return length();
     }
     if (newpos > len || newpos < 0)
-        return false;
+        return -1;
     pos = newpos;
-    return true;
+    return newpos;
 }
 
 long MMapFile::position() const {
diff --git a/akode/lib/mmapfile.h b/akode/lib/mmapfile.h
index 80c5913..c2de99f 100644
--- a/akode/lib/mmapfile.h
+++ b/akode/lib/mmapfile.h
@@ -47,7 +47,7 @@ public:
     long read(char* ptr, long num);
     long write(const char*, long);
 
-    bool seek(long to, int whence = SEEK_SET);
+    ssize_t seek(long to, int whence = SEEK_SET);
     long position() const;
     long length() const;