Edge Cases and Advanced Scenarios

import fdb

fdb.api_version(740)
db = fdb.open()

@fdb.transactional
def long_operation(tr):
    """Handle transaction timeout for long operations."""
    # Set longer timeout
    tr.options.set_timeout(10000)  # 10 seconds
    
    # Break into smaller operations if needed
    for i in range(1000):
        tr[b'key' + str(i).encode()] = b'value'
        # Check approximate size periodically
        if tr.get_approximate_size().wait() > 8000000:  # 8 MB
            # Transaction too large, commit and continue
            raise fdb.FDBError(1020)  # Force retry with new transaction

# Alternative: Break into multiple transactions
def process_large_dataset(db, items):
    """Process large dataset across multiple transactions."""
    batch_size = 100
    for i in range(0, len(items), batch_size):
        batch = items[i:i + batch_size]
        @fdb.transactional
        def process_batch(tr):
            for item in batch:
                tr[item.key] = item.value
        process_batch(db)

import fdb

fdb.api_version(740)
db = fdb.open()

def idempotent_operation(db, key, value, operation_id):
    """Handle commit_unknown_result with idempotent operations."""
    @fdb.transactional
    def set_with_id(tr):
        # Check if operation already completed
        existing_op_id = tr.get(key + b':op_id')
        if existing_op_id and existing_op_id.wait() == operation_id.encode():
            return True  # Already completed
        
        # Perform operation
        tr[key] = value
        tr[key + b':op_id'] = operation_id.encode()
        return False
    
    try:
        already_done = set_with_id(db, key, value, operation_id)
        if already_done:
            print("Operation already completed")
    except fdb.FDBError as e:
        if e.code == 1021:  # commit_unknown_result
            # Check if operation succeeded
            @fdb.transactional
            def check_result(tr):
                return tr.get(key + b':op_id').wait() == operation_id.encode()
            
            if check_result(db):
                print("Operation succeeded")
            else:
                # Retry
                set_with_id(db, key, value, operation_id)

import fdb
import fdb.tuple as fdb_tuple

fdb.api_version(740)
db = fdb.open()

def create_ordered_sequence(db, prefix, items):
    """Create ordered sequence using versionstamps."""
    results = []
    
    for item in items:
        tr = db.create_transaction()
        
        # Create incomplete versionstamp
        vs = fdb_tuple.Versionstamp.incomplete()
        key = fdb_tuple.pack_with_versionstamp((prefix, vs))
        
        # Set versionstamped key
        tr.set_versionstamped_key(key, item.encode())
        
        # Get versionstamp future
        vs_future = tr.get_versionstamp()
        
        try:
            tr.commit().wait()
            # Wait for versionstamp to be available
            versionstamp = vs_future.wait()
            results.append((versionstamp, item))
        except fdb.FDBError as e:
            if e.code == 1021:  # commit_unknown_result
                # Check if key exists with versionstamp
                # Retry if needed
                pass
    
    return results

import fdb

fdb.api_version(740)
db = fdb.open()

@fdb.transactional
def safe_range_read(tr, begin_key, end_key):
    """Handle empty ranges safely."""
    if begin_key >= end_key:
        return []  # Empty range
    
    results = []
    for kv in tr.get_range(begin_key, end_key, limit=1000):
        results.append((kv.key, kv.value))
    
    return results

import fdb

fdb.api_version(740)
db = fdb.open()

MAX_KEY_SIZE = 10000
MAX_VALUE_SIZE = 100000

def safe_set(tr, key, value):
    """Set key-value with size validation."""
    if len(key) > MAX_KEY_SIZE:
        raise ValueError(f"Key too large: {len(key)} > {MAX_KEY_SIZE}")
    
    if len(value) > MAX_VALUE_SIZE:
        raise ValueError(f"Value too large: {len(value)} > {MAX_VALUE_SIZE}")
    
    tr[key] = value

# For large values, split into chunks
def set_large_value(tr, base_key, large_value, chunk_size=90000):
    """Split large value into chunks."""
    chunks = [large_value[i:i+chunk_size] 
              for i in range(0, len(large_value), chunk_size)]
    
    # Store chunk count
    tr[base_key + b':count'] = str(len(chunks)).encode()
    
    # Store chunks
    for i, chunk in enumerate(chunks):
        tr[base_key + b':chunk:' + str(i).encode()] = chunk

import fdb
import fdb.tenant_management

fdb.api_version(740)
db = fdb.open()

def get_or_create_tenant(db, tenant_name):
    """Get tenant or create if doesn't exist."""
    try:
        tenant = db.open_tenant(tenant_name)
        return tenant
    except fdb.FDBError as e:
        if e.code == 2131:  # tenant_not_found
            # Create tenant
            fdb.tenant_management.create_tenant(db, tenant_name)
            return db.open_tenant(tenant_name)
        else:
            raise

# Usage
tenant = get_or_create_tenant(db, b'company_a')

import fdb

fdb.api_version(740)
db = fdb.open()

def safe_directory_operations(db, path):
    """Handle directory operations with error checking."""
    try:
        # Try to open directory
        directory = fdb.directory.open(db, path)
        return directory
    except fdb.FDBError:
        # Directory doesn't exist, create it
        try:
            directory = fdb.directory.create(db, path)
            return directory
        except fdb.FDBError as e:
            if e.code == 2010:  # directory_already_exists
                # Race condition: directory created between open and create
                return fdb.directory.open(db, path)
            raise

# Handle directory removal with children
def remove_directory_safe(db, path):
    """Remove directory only if empty."""
    @fdb.transactional
    def check_and_remove(tr):
        # Check if directory has children
        children = fdb.directory.list(tr, path)
        if children:
            raise ValueError(f"Directory {path} has children: {children}")
        
        # Remove directory
        fdb.directory.remove(tr, path)
    
    try:
        check_and_remove(db, path)
    except ValueError as e:
        print(f"Cannot remove: {e}")

import fdb

fdb.api_version(740)
db = fdb.open()

def watch_with_timeout(db, key, timeout_seconds=30):
    """Watch key with timeout."""
    import time
    
    tr = db.create_transaction()
    watch_future = tr.watch(key)
    tr.commit().wait()
    
    start_time = time.time()
    while not watch_future.is_ready():
        if time.time() - start_time > timeout_seconds:
            watch_future.cancel()
            raise TimeoutError("Watch timeout")
        time.sleep(0.1)
    
    watch_future.wait()
    return True

import fdb

fdb.api_version(740)
db = fdb.open()

def consistent_snapshot_read(db, key):
    """Read from consistent snapshot version."""
    tr1 = db.create_transaction()
    read_version = tr1.get_read_version().wait()
    
    # Use same read version for snapshot
    tr2 = db.create_transaction()
    tr2.set_read_version(read_version)
    
    # Snapshot read at specific version
    value = tr2.snapshot.get(key).wait()
    return value

import fdb

fdb.api_version(740)
db = fdb.open()

def robust_operation(db, operation_func, max_retries=10):
    """Robust operation with explicit retry handling."""
    for attempt in range(max_retries):
        try:
            return operation_func(db)
        except fdb.FDBError as e:
            if e.code == 1020:  # not_committed
                if attempt < max_retries - 1:
                    continue  # Retry
                else:
                    raise
            elif e.code == 1021:  # commit_unknown_result
                # Check if operation succeeded
                # Implement idempotent check
                raise
            else:
                # Non-retryable error
                raise