Struct pgx::stringinfo::StringInfo

pub struct StringInfo { /* fields omitted */ }

StringInfoData holds information about an extensible string that is allocated by Postgres' memory system, but generally follows Rust's drop semantics

Implementations

impl StringInfo

pub fn new() -> Self

Construct a new StringInfo of its default size, allocated by Postgres in CurrentMemoryContext

Unless .into_pg() or .into_char_ptr() are called, memory management of this StringInfo follow Rust's drop semantics.

pub fn with_capacity(len: usize) -> Self

Construct a new StringInfo, allocated by Postgres in CurrentMemoryContext, ensuring it has a capacity of the specified len.

Note that Postgres can only represent up to 1 gigabyte of data in a StringInfo

Unless .into_pg() or .into_char_ptr() are called, memory management of this StringInfo follow Rust's drop semantics.

pub fn from_pg(sid: StringInfo) -> Option<Self>

Construct a StringInfo from a Postgres-allocated pg_sys::StringInfo.

The backing pg_sys::StringInfo structure will be freed whenever the memory context in which it was originally allocated is reset.

pub fn len(&self) -> usize

What is the length, excluding the trailing null byte

pub fn is_empty(&self) -> bool

Do we have any characters?

pub fn push(&mut self, ch: char)

Push a Rust character onto the end. A Rust char could be 4 bytes in total, so it is converted into a String first to ensure unicode correctness

pub fn push_str(&mut self, s: &str)

Push a String reference onto the end

pub fn push_bytes(&mut self, bytes: &[u8])

Push arbitrary bytes onto the end. Any byte sequence is allowed, include those with embedded NULLs

pub fn push_raw(&mut self, ptr: void_mut_ptr, len: usize)

Push the bytes behind a raw pointer of a given length onto the end

pub fn reset(&mut self)

Reset the size of the StringInfo back to zero-length. This does/// not* free any previously-allocated memory

pub fn enlarge(&mut self, needed: usize)

Ensure that this StringInfo is at least needed bytes long

pub fn as_ptr(&self) -> *mut c_char

A pointer representation

pub fn as_bytes(&self) -> &[u8]

A &[u8] byte slice representation

pub fn as_bytes_mut(&mut self) -> &mut [u8]

A mutable &[u8] byte slice representation

pub fn into_pg(mut self: Self) -> *mut StringInfoData

Convert this StringInfo into one that is wholly owned and now managed by Postgres

pub fn into_char_ptr(mut self: Self) -> *const c_char

Convert this StringInfo into a "char *" that is wholly owned and now managed by Postgres

Trait Implementations

impl Default for StringInfo

pub fn default() -> Self

Returns the "default value" for a type.

impl Drop for StringInfo

pub fn drop(&mut self)

Executes the destructor for this type.

impl From<&'_ [u8]> for StringInfo

pub fn from(v: &[u8]) -> Self

Performs the conversion.

impl From<&'_ str> for StringInfo

pub fn from(s: &str) -> Self

Performs the conversion.

impl From<String> for StringInfo

pub fn from(s: String) -> Self

Performs the conversion.

impl From<Vec<u8, Global>> for StringInfo

pub fn from(v: Vec<u8>) -> Self

Performs the conversion.

impl Into<&'static CStr> for StringInfo

pub fn into(self) -> &'static CStr

Performs the conversion.

impl Into<*mut StringInfoData> for StringInfo

pub fn into(self) -> StringInfo

Performs the conversion.

impl ToString for StringInfo

pub fn to_string(&self) -> String

Converts the given value to a String.

impl Write for StringInfo

pub fn write(&mut self, buf: &[u8]) -> Result<usize, Error>

Write a buffer into this writer, returning how many bytes were written.

pub fn flush(&mut self) -> Result<(), Error>

Flush this output stream, ensuring that all intermediately buffered contents reach their destination.

pub fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> Result<usize, Error>

Like write, except that it writes from a slice of buffers.

pub fn is_write_vectored(&self) -> bool

🔬 This is a nightly-only experimental API. (can_vector)

Determines if this Writer has an efficient write_vectored implementation.

pub fn write_all(&mut self, buf: &[u8]) -> Result<(), Error>

Attempts to write an entire buffer into this writer.

pub fn write_all_vectored(
    &mut self,
    bufs: &mut [IoSlice<'_>]
) -> Result<(), Error>

🔬 This is a nightly-only experimental API. (write_all_vectored)

Attempts to write multiple buffers into this writer.

pub fn write_fmt(&mut self, fmt: Arguments<'_>) -> Result<(), Error>

Writes a formatted string into this writer, returning any error encountered.

pub fn by_ref(&mut self) -> &mut Self

Creates a "by reference" adaptor for this instance of Write.