From 7e7cede8b1209e71b151cc872e647a2ba3d7eade Mon Sep 17 00:00:00 2001
From: m-holger <m.holger@qpdf.org>
Date: Wed, 4 Jun 2025 13:50:42 +0100
Subject: [PATCH] Refactor `is::OffsetBuffer` to rename `cur_offset` to `pos` and consolidate redundant methods for improved code clarity.

---
 libqpdf/BufferInputSource.cc        | 46 +++++++++++++++++++++++-----------------------
 libqpdf/qpdf/InputSource_private.hh | 29 +++++++----------------------
 2 files changed, 30 insertions(+), 45 deletions(-)

diff --git a/libqpdf/BufferInputSource.cc b/libqpdf/BufferInputSource.cc
index af2c6bc..71390cf 100644
--- a/libqpdf/BufferInputSource.cc
+++ b/libqpdf/BufferInputSource.cc
@@ -146,57 +146,57 @@ BufferInputSource::unreadCh(char ch)
 }
 
 qpdf_offset_t
-is::OffsetBuffer::findAndSkipNextEOL_internal()
+is::OffsetBuffer::findAndSkipNextEOL()
 {
-    if (cur_offset < 0) {
+    if (pos < 0) {
         throw std::logic_error("INTERNAL ERROR: is::OffsetBuffer offset < 0");
     }
     auto end_pos = static_cast<qpdf_offset_t>(view_.size());
-    if (cur_offset >= end_pos) {
+    if (pos >= end_pos) {
         last_offset = end_pos + global_offset;
-        cur_offset = end_pos;
-        return end_pos;
+        pos = end_pos;
+        return end_pos + global_offset;
     }
 
     qpdf_offset_t result = 0;
     auto buffer = view_.begin();
     auto end = view_.end();
-    auto p = buffer + cur_offset;
+    auto p = buffer + pos;
 
     while (p < end && !(*p == '\r' || *p == '\n')) {
         ++p;
     }
     if (p < end) {
         result = p - buffer;
-        cur_offset = result + 1;
+        pos = result + 1;
         ++p;
-        while (cur_offset < end_pos && (*p == '\r' || *p == '\n')) {
+        while (pos < end_pos && (*p == '\r' || *p == '\n')) {
             ++p;
-            ++cur_offset;
+            ++pos;
         }
     } else {
-        cur_offset = end_pos;
+        pos = end_pos;
         result = end_pos;
     }
-    return result;
+    return result + global_offset;
 }
 
 void
-is::OffsetBuffer::seek_internal(qpdf_offset_t offset, int whence)
+is::OffsetBuffer::seek(qpdf_offset_t offset, int whence)
 {
     switch (whence) {
     case SEEK_SET:
-        cur_offset = offset;
+        pos = offset - global_offset;
         break;
 
     case SEEK_END:
         QIntC::range_check(static_cast<qpdf_offset_t>(view_.size()), offset);
-        cur_offset = static_cast<qpdf_offset_t>(view_.size()) + offset;
+        pos = static_cast<qpdf_offset_t>(view_.size()) + offset;
         break;
 
     case SEEK_CUR:
-        QIntC::range_check(cur_offset, offset);
-        cur_offset += offset;
+        QIntC::range_check(pos, offset);
+        pos += offset;
         break;
 
     default:
@@ -204,7 +204,7 @@ is::OffsetBuffer::seek_internal(qpdf_offset_t offset, int whence)
         break;
     }
 
-    if (cur_offset < 0) {
+    if (pos < 0) {
         throw std::runtime_error(description + ": seek before beginning of buffer");
     }
 }
@@ -212,18 +212,18 @@ is::OffsetBuffer::seek_internal(qpdf_offset_t offset, int whence)
 size_t
 is::OffsetBuffer::read(char* buffer, size_t length)
 {
-    if (cur_offset < 0) {
+    if (pos < 0) {
         throw std::logic_error("INTERNAL ERROR: is::OffsetBuffer offset < 0");
     }
     auto end_pos = static_cast<qpdf_offset_t>(view_.size());
-    if (cur_offset >= end_pos) {
+    if (pos >= end_pos) {
         last_offset = end_pos + global_offset;
         return 0;
     }
 
-    last_offset = cur_offset + global_offset;
-    size_t len = std::min(QIntC::to_size(end_pos - cur_offset), length);
-    memcpy(buffer, view_.data() + cur_offset, len);
-    cur_offset += QIntC::to_offset(len);
+    last_offset = pos + global_offset;
+    size_t len = std::min(QIntC::to_size(end_pos - pos), length);
+    memcpy(buffer, view_.data() + pos, len);
+    pos += QIntC::to_offset(len);
     return len;
 }
diff --git a/libqpdf/qpdf/InputSource_private.hh b/libqpdf/qpdf/InputSource_private.hh
index 800530a..a52bcb3 100644
--- a/libqpdf/qpdf/InputSource_private.hh
+++ b/libqpdf/qpdf/InputSource_private.hh
@@ -30,11 +30,7 @@ namespace qpdf::is
 
         ~OffsetBuffer() final = default;
 
-        qpdf_offset_t
-        findAndSkipNextEOL() final
-        {
-            return findAndSkipNextEOL_internal() + global_offset;
-        }
+        qpdf_offset_t findAndSkipNextEOL() final;
 
         std::string const&
         getName() const final
@@ -45,23 +41,15 @@ namespace qpdf::is
         qpdf_offset_t
         tell() final
         {
-            return cur_offset + global_offset;
+            return pos + global_offset;
         }
 
-        void
-        seek(qpdf_offset_t offset, int whence) final
-        {
-            if (whence == SEEK_SET) {
-                seek_internal(offset - global_offset, whence);
-            } else {
-                seek_internal(offset, whence);
-            }
-        }
+        void seek(qpdf_offset_t offset, int whence) final;
 
         void
         rewind() final
         {
-            seek_internal(0, SEEK_SET);
+            pos = 0;
         }
 
         size_t read(char* buffer, size_t length) final;
@@ -69,17 +57,14 @@ namespace qpdf::is
         void
         unreadCh(char ch) final
         {
-            if (cur_offset > 0) {
-                --cur_offset;
+            if (pos > 0) {
+                --pos;
             }
         }
 
       private:
-        qpdf_offset_t findAndSkipNextEOL_internal();
-        void seek_internal(qpdf_offset_t offset, int whence);
-
         std::string description;
-        qpdf_offset_t cur_offset{0};
+        qpdf_offset_t pos{0};
         std::string_view view_;
         qpdf_offset_t global_offset;
     };
--
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