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author | Juan Manuel Tomás <jtomas1815@gmail.com> | 2020-07-17 16:23:43 -0300 |
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committer | Juan Manuel Tomás <jtomas1815@gmail.com> | 2020-07-17 16:23:43 -0300 |
commit | d608bef678fa97b3af910fa62598c55f33650825 (patch) | |
tree | 90f1b4029be89a3ed3c55593b9787371c8037a35 /src/server/point.cpp | |
parent | c1d93b0bc5a2abcf5e7cadd17ef9db7f57a524fc (diff) | |
download | jet-d608bef678fa97b3af910fa62598c55f33650825.tar.gz jet-d608bef678fa97b3af910fa62598c55f33650825.zip |
Restructure source files
Diffstat (limited to 'src/server/point.cpp')
-rw-r--r-- | src/server/point.cpp | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/src/server/point.cpp b/src/server/point.cpp new file mode 100644 index 0000000..ab9f70f --- /dev/null +++ b/src/server/point.cpp @@ -0,0 +1,139 @@ +#include <stdint.h> +#include <stdbool.h> + +struct Point { + Page *page; + uint16_t index; + + uint16_t index_to_offset() { + if (index < page->gap_start) { + return index; + } else { + return index + (page->gap_end - page->gap_start); + } + } + + uint8_t prev_byte() { + if (index == 0) { + if (page->prev) { + return page->prev->elements[Point(page->prev, page->prev->element_count - 1).index_to_offset()]; + } else { + return 0; + } + } else { + return page->elements[Point(page, index - 1).index_to_offset()]; + } + } + + uint8_t next_byte() { + if (index == page->element_count) { + if (page->next) { + return page->next->elements[Point(page->next, 0).index_to_offset()]; + } else { + return 0; + } + } else { + return page->elements[index_to_offset()]; + } + } + + void move_forward() { + if (index < page->element_count) { + index++; + } else if (page->next) { + page = page->next; + index = 0; + } + } + + void move_backward() { + if (index > 0) { + index--; + } else if (page->prev) { + page = page->prev; + index = page->element_count; + } + } + + + public: + + Point() : page(0), index(0) {} + Point(Page* page, uint16_t index) : page(page), index(index) {} + Point(const Buffer &b) : page(b.storage), index(0) {} + Point(const Point &p) : page(p.page), index(p.index) {} + + bool operator==(Point p) { + return page == p.page && index == p.index; + } + + bool operator!=(Point p) { + return page != p.page || index != p.index; + } + + bool at_start() { + return index == 0 && !page->prev; + } + + bool at_end() { + return index == page->element_count && !page->next; + } + + void operator++(int) { + if (index == page->element_count) move_forward(); + move_forward(); + } + + void operator--(int) { + move_backward(); + if (index == 0) move_backward(); + } + + char element() { + return next_byte(); + } + + void align_gap() { + while (page->gap_end < index_to_offset()) { + page->move_gap_forward(); + } + while (page->gap_end > index_to_offset()) { + page->move_gap_backward(); + } + } + + void push(uint8_t c) { + if (page->is_full()) { + page->split(); + if (index >= PAGE_SIZE / 2) { + page = page->next; + index -= PAGE_SIZE / 2; + } + } + align_gap(); + page->push(c); + move_forward(); + } + + void pop() { + if (!at_start()) { + align_gap(); + page->pop(); + move_backward(); + if (index == 0) { + move_backward(); + } + } + if (page->is_empty()) { + if (page->prev) { + move_backward(); + delete page->next; + } else if (page->next) { + page->next->copy_to(page); + delete page->next; + index = 0; + } + } + } + +}; |