libpgdump 2.1.0

# libpgdump

A Rust library for reading and writing PostgreSQL dump files.

Supports all three pg_dump formats: **custom** (`-Fc`), **directory** (`-Fd`),
and **tar** (`-Ft`).

## Usage

Add to your `Cargo.toml`:

```toml
[dependencies]
libpgdump = "1"
```

### Load an existing dump

```rust
use libpgdump;

let dump = libpgdump::load("backup.dump").unwrap();

println!("Database: {}", dump.dbname());
println!("Server:   {}", dump.server_version());
println!("Entries:  {}", dump.entries().len());

// Iterate over table data
for row in dump.table_data("public", "users").unwrap() {
    println!("{row}");  // tab-separated COPY format
}

// Look up a specific entry
if let Some(entry) = dump.lookup_entry(&libpgdump::ObjectType::Table, "public", "users") {
    println!("Definition: {}", entry.defn.as_deref().unwrap_or(""));
}
```

### Create a new dump

```rust
use libpgdump;

let mut dump = libpgdump::new("mydb", "UTF8", "17.0").unwrap();

// Add a table definition
let table_id = dump.add_entry(
    libpgdump::ObjectType::Table,
    Some("public"), Some("users"), Some("postgres"),
    Some("CREATE TABLE public.users (\n    id integer NOT NULL,\n    name text\n);\n"),
    Some("DROP TABLE public.users;\n"),
    None, &[],
).unwrap();

// Add table data
let data_id = dump.add_entry(
    libpgdump::ObjectType::TableData,
    Some("public"), Some("users"), Some("postgres"),
    None, None,
    Some("COPY public.users (id, name) FROM stdin;\n"),
    &[table_id],
).unwrap();

dump.set_entry_data(data_id, b"1\tAlice\n2\tBob\n".to_vec()).unwrap();

// Save with gzip compression
dump.set_compression(libpgdump::CompressionAlgorithm::Gzip);
dump.save("output.dump").unwrap();
```

### Inspect entries

```rust
use libpgdump;

let dump = libpgdump::load("backup.dump").unwrap();

for entry in dump.entries() {
    println!(
        "{:>4} {:20} {:10} {}",
        entry.dump_id,
        entry.desc,
        entry.namespace.as_deref().unwrap_or(""),
        entry.tag.as_deref().unwrap_or(""),
    );
}
```

### Error handling

```rust
use libpgdump::{self, Error};

match libpgdump::load("backup.dump") {
    Ok(dump) => println!("Loaded {} entries", dump.entries().len()),
    Err(Error::InvalidHeader(msg)) => eprintln!("Not a valid dump: {msg}"),
    Err(Error::UnsupportedVersion(v)) => eprintln!("Unsupported version: {v}"),
    Err(e) => eprintln!("Error: {e}"),
}
```

## Supported features

- **Read/write** custom (`-Fc`), directory (`-Fd`), and tar (`-Ft`) archives
- **Compression**: none, gzip, lz4, and zstd
- **Archive versions** 1.12.0 through 1.16.0 (PostgreSQL 9.0–18)
- **Version-aware parsing**: handles all format variations across versions
- **60+ object types**: tables, indexes, views, functions, constraints, extensions, etc.
- **Large object (blob) support**
- **Weighted topological sort**: entries are sorted on save matching pg_dump's dependency-aware ordering
- **Programmatic dump creation**: build dumps from scratch with the builder API

## Format details

`Dump::load()` auto-detects the format from file type (directory) or magic bytes (`PGDMP` = custom, `ustar` = tar).

### Custom format (`-Fc`)

Binary archive: header with magic bytes, version, and compression info; metadata (timestamp, database name, versions); TOC with entry definitions and dependencies; compressed or uncompressed data blocks.

### Directory format (`-Fd`)

A directory containing `toc.dat` (binary TOC in custom format) and per-entry `.dat` data files. Supports all compression algorithms.

### Tar format (`-Ft`)

A standard tar archive containing `toc.dat` and per-entry data files. Does not support compression.

## Minimum Rust version

Rust 1.88 or later (edition 2024).

## License

BSD-3-Clause