Implementation:InternLM Lmdeploy Interval

Knowledge Sources	InternLM_Lmdeploy
Domains	Data_Structures, Core_Infrastructure
Last Updated	2026-02-07 15:00 GMT

Overview

Provides a half-open integer interval class [first, last) with intersection, union, dilation/erosion, and size query operations.

Description

The Interval class represents a half-open integer range [first_, last_). It supports construction from a single start value (open-ended, using INT_MAX), a pair of endpoints, or a start plus Size wrapper. Key operations include: empty() for checking if the interval has zero or negative extent, size() returning a Size struct, begin()/end() for the endpoints, operator& for intersection, operator| for union (bounding box), and left/right dilation via int | Interval and Interval | int. The Size nested struct wraps an int with an explicit conversion operator and comparison support.

Usage

Used in TurboMind for representing token index ranges, sequence position windows, and KV-cache slot ranges during attention computation and sequence scheduling.

Code Reference

Source Location

• Repository: InternLM_Lmdeploy
• File: src/turbomind/core/interval.h
• Lines: 1-95

Signature

namespace turbomind {

class Interval {
public:
    struct Size {
        int x;
        explicit operator int() const noexcept;
    };

    Interval();                          // empty [0, 0)
    explicit Interval(int first);        // [first, INT_MAX)
    Interval(int first, int last);       // [first, last)
    Interval(int first, Size size);      // [first, first+size)

    bool empty() const noexcept;
    explicit operator bool() const noexcept;
    Size size() const noexcept;
    int begin() const noexcept;
    int end() const noexcept;

    friend Interval operator&(const Interval& a, const Interval& b);  // intersection
    friend Interval operator|(const Interval& a, const Interval& b);  // union
    friend Interval operator|(int x, const Interval& a);              // dilate left
    friend Interval operator|(const Interval& a, int x);              // dilate right
};

}  // namespace turbomind

Import

#include "src/turbomind/core/interval.h"

I/O Contract

Inputs

Name	Type	Required	Description
first	int	Yes	Start of the interval (inclusive)
last	int	Conditional	End of the interval (exclusive); or use Size
size	Size	Conditional	Extent of the interval

Outputs

Name	Type	Description
empty()	bool	True if the interval has zero or negative extent
size()	Size	Number of integers in the interval
begin()	int	First element (inclusive)
end()	int	Past-the-end element (exclusive)

Usage Examples

#include "src/turbomind/core/interval.h"

using turbomind::Interval;

Interval a(10, 20);   // [10, 20)
Interval b(15, 25);   // [15, 25)

auto inter = a & b;   // [15, 20) - intersection
auto uni   = a | b;   // [10, 25) - union

int sz = (int)a.size();  // 10

// Dilate right by 5
auto dilated = a | 5;    // [10, 25)

Related Pages

• Environment:InternLM_Lmdeploy_CUDA_GPU_Runtime