Cache Example

Standalone Cache for parsed values (no longer owned by Env).

Source Code

const std = @import("std");
const Io = std.Io;
const envMod = @import("env");

pub fn main(init: std.process.Init) !void {
    const io = init.io;
    const allocator = init.gpa;

    var env = envMod.Env.init(allocator, .{});
    defer env.deinit();

    try env.parseString(
        \\API_KEY=secret123
        \\DATABASE_URL=postgres://localhost/mydb
        \\PORT=8080
        \\
    );

    var stdoutBuffer: [0x100]u8 = undefined;
    var stdoutWriter = Io.File.stdout().writer(io, &stdoutBuffer);
    const stdout = &stdoutWriter.interface;

    try stdout.print("=== Cache Example ===\n\n", .{});

    var cache = envMod.Cache.init(allocator);
    defer cache.deinit();

    try cache.put("cached_token", "abc123");
    try cache.put("cached_config", "{ \"timeout\": 30 }");

    try stdout.print("Cache count: {d}\n", .{cache.count()});

    if (cache.get("cached_token")) |token| {
        try stdout.print("Cached token: {s}\n", .{token});
    }

    try stdout.print("Has cached_token: {}\n", .{cache.contains("cached_token")});
    try stdout.print("Has missing: {}\n", .{cache.contains("missing")});

    try cache.put("cached_token", "new_token_456");
    try stdout.print("Updated token: {s}\n", .{cache.get("cached_token").?});

    _ = cache.remove("cached_config");
    try stdout.print("After remove, has cached_config: {}\n", .{cache.contains("cached_config")});
    try stdout.print("Cache count after remove: {d}\n", .{cache.count()});

    cache.clear();
    try stdout.print("Cache count after clear: {d}\n", .{cache.count()});

    try stdout.print("\nEnv entries still intact:\n", .{});
    for (env.keys()) |key| {
        try stdout.print("  {s} = {s}\n", .{ key, env.get(key).? });
    }
    try stdout.flush();
}

Running

zig-out/bin/cache_example

Example Output

=== Cache Example ===

Cache count: 2
Cached token: abc123
Has cached_token: true
Has missing: false
Updated token: new_token_456
After remove, has cached_config: false
Cache count after remove: 1
Cache count after clear: 0

Env entries still intact:
  API_KEY = secret123
  DATABASE_URL = postgres://localhost/mydb
  PORT = 8080

Before / After

Cache state transitions during the run:

# after two puts
cached_token=abc123
cached_config={ "timeout": 30 }

# after overwrite + remove + clear
# (empty — count 0)

The Env store is untouched throughout:

API_KEY=secret123
DATABASE_URL=postgres://localhost/mydb
PORT=8080

See Also

• Cache Guide for usage details
• API Reference for the full API