move ring_buffer.h from debug_log into util; debug_log links util PUBLIC

debug_log/CMakeLists.txt

@@ -4,4 +4,4 @@ target_include_directories(debug_log PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})
 
 target_compile_options(debug_log PRIVATE -Wall -Wextra -Wno-unused-parameter)
 
-target_link_libraries(debug_log PUBLIC pico_stdlib)
+target_link_libraries(debug_log PUBLIC util pico_stdlib)

debug_log/ring_buffer.h

@@ -1,70 +0,0 @@
-#pragma once
-#include <array>
-#include <cstdint>
-#include <span>
-
-// Fixed-capacity FIFO with wrap-around. push_overwrite drops the oldest entry
-// when full -- used by the debug log so dlog never blocks or fails. Iteration
-// walks logical positions head..tail, hiding the modular indexing.
-template <typename T, uint16_t N>
-struct ring_buffer {
-    std::array<T, N> data = {};
-    uint16_t head = 0;
-    uint16_t tail = 0;
-
-    uint16_t used() const { return tail - head; }
-    uint16_t free() const { return N - used(); }
-    bool empty() const { return head == tail; }
-
-    bool push(std::span<const T> src) {
-        if (src.size() > free()) return false;
-        for (auto& v : src)
-            data[(tail++) % N] = v;
-        return true;
-    }
-
-    bool push(const T& v) {
-        if (free() == 0) return false;
-        data[(tail++) % N] = v;
-        return true;
-    }
-
-    void push_overwrite(const T& v) {
-        if (free() == 0) head++;
-        data[(tail++) % N] = v;
-    }
-
-    uint16_t peek(std::span<T> dst) const {
-        uint16_t len = dst.size() < used() ? dst.size() : used();
-        for (uint16_t i = 0; i < len; i++)
-            dst[i] = data[(head + i) % N];
-        return len;
-    }
-
-    void consume(uint16_t len) {
-        head += len;
-        if (head >= N) {
-            head -= N;
-            tail -= N;
-        }
-    }
-
-    std::span<const T> read_contiguous() const {
-        uint16_t offset = head % N;
-        uint16_t contig = N - offset;
-        uint16_t pending = used();
-        uint16_t len = pending < contig ? pending : contig;
-        return {data.data() + offset, len};
-    }
-
-    struct iterator {
-        const ring_buffer* rb;
-        uint16_t index;
-        const T& operator*() const { return rb->data[(rb->head + index) % N]; }
-        iterator& operator++() { index++; return *this; }
-        bool operator!=(const iterator& o) const { return index != o.index; }
-    };
-
-    iterator begin() const { return {this, 0}; }
-    iterator end() const { return {this, used()}; }
-};