Viper_VRTE/requests/__init__.vp

import string
import socket
import memhub
import stdio
import stdlib
import zlib.pyzlib as pyzlib


# ============================================================
# requests/__init__.vp - HTTP(S) client library package entry point (Python requests style)
#
# Package structure:
#   requests          HTTP  client (pure socket implementation, this file)
#   requests.https    HTTPS client (openssl SSL/TLS + certificate verification, see https.vp)
#
# Usage:
#     requests._mbuddy = my_mbuddy
#     resp = requests.get("http://example.com/path")
#     if resp is not None:
#         print(resp.status_code)
#         print(resp.text)
#     requests.release(resp)
# ============================================================

# Module-level global MBuddy pointer (assigned by the user in main)
_mbuddy: memhub.MemBuddy*

# Socket initialization flag
_socket_ready: bool = False

define HTTP_PORT = 80
define HTTP_BUFSIZ = 4096
define GZIP_BUFSIZ = 65536

# Module-internal redirect / failure diagnostics (static buffer)
_http_err_store: [512]char


def last_error() -> str:
    """Last HTTP-layer failure reason (empty string if none)."""
    return _http_err_store


def _SetHttpError(text: str):
    if text is None: return
    _http_err_store[0] = 0
    stdio.snprintf(_http_err_store, 512, "%s", text)


# ============================================================
# Response — HTTP response object
# ============================================================

class Response:
    """HTTP response object, similar to how Python's requests.Response works.

    Allocated from _mbuddy, call release(resp) to free it after use.
    """
    status_code: int       # HTTP status code (e.g., 200, 404)
    text: str              # Response body text
    body_len: int          # Response body length
    _raw_buf: str          # raw response buffer (headers+body, freed by release)
    _body_owned: str       # separately decoded body buffer (chunked etc., freed by release)


# ============================================================
# internal auxiliary functions
# ============================================================

def _EnsureSocketInit() -> int:
    """Ensure Socket library is initialized (idempotent)."""
    global _socket_ready
    if _socket_ready: return 0
    result: int = socket.SocketInit()
    if result == 0:
        _socket_ready = True
    return result


def _AllocResponse() -> Response*:
    """Allocate Response struct from _mbuddy and initialize it in-place."""
    if _mbuddy is None: return None
    resp: Response* = _mbuddy.alloc(Response.__sizeof__())
    if resp is None: return None
    resp.status_code = 0
    resp.text = None
    resp.body_len = 0
    resp._raw_buf = None
    resp._body_owned = None
    return resp


def _ParseUrl(url: str, host_buf: str, host_size: int, path_buf: str, path_size: int, port: int*) -> int:
    """Parse URL and extract host, port, and path."""
    if url is None: return -1
    if host_buf is None or path_buf is None or port is None: return -1

    p: str = url

    # Skip "http://"
    if string.strncmp(p, "http://", 7) == 0:
        p += 7

    # Parse host
    host_start: str = p
    host_len: int = 0
    while p[0] != '\0' and p[0] != ':' and p[0] != '/':
        host_len += 1
        p += 1

    if host_len == 0 or host_len >= host_size: return -1
    string.strncpy(host_buf, host_start, host_len)
    host_buf[host_len] = 0

    # Parse port
    if p[0] == ':':
        p += 1
        port_val: int = 0
        while p[0] >= '0' and p[0] <= '9':
            port_val = port_val * 10 + int(p[0] - '0')
            p += 1
        *port = port_val
    else:
        *port = HTTP_PORT

    # Parse path
    if p[0] == '/':
        path_start: str = p
        path_len: int = 0
        while p[0] != '\0':
            path_len += 1
            p += 1
        if path_len >= path_size: return -1
        string.strncpy(path_buf, path_start, path_len)
        path_buf[path_len] = 0
    else:
        if path_size < 2: return -1
        path_buf[0] = '/'
        path_buf[1] = 0

    return 0


def _ParseStatusLine(resp_text: str, out_code: int*) -> int:
    """Parse HTTP status line and extract status code."""
    if resp_text is None or out_code is None: return -1

    p: str = resp_text

    # Skip "HTTP/x.x "
    while p[0] != '\0' and p[0] != ' ':
        p += 1
    if p[0] == ' ': p += 1

    # Parse status code
    code: int = 0
    while p[0] >= '0' and p[0] <= '9':
        code = code * 10 + int(p[0] - '0')
        p += 1

    *out_code = code

    # Find \n
    while p[0] != '\0' and p[0] != '\n':
        p += 1
    if p[0] == '\n': p += 1

    return int(uint64(p) - uint64(resp_text))


def _FindBodyStart(resp_text: str, resp_len: int) -> int:
    """Find the start of the HTTP response body (after rnrn)."""
    if resp_text is None: return -1

    end_of_headers: str = string.strstr(resp_text, "\r\n\r\n")
    if end_of_headers is None:
        end_of_headers = string.strstr(resp_text, "\n\n")
        if end_of_headers is None:
            return -1
        return int(uint64(end_of_headers) - uint64(resp_text)) + 2

    return int(uint64(end_of_headers) - uint64(resp_text)) + 4


# ============================================================
# Public helpers (reused by requests.https and other submodules)
# ============================================================

def create_response() -> Response*:
    """Create and initialize an empty HTTP Response (allocated from _mbuddy).

    Call release(resp) to free it after use.
    """
    return _AllocResponse()


def parse_status_line(resp_text: str, out_code: int*) -> int:
    """Parse HTTP status line, write status code into out_code."""
    return _ParseStatusLine(resp_text, out_code)


def find_body_start(resp_text: str, resp_len: int) -> int:
    """Locate the start of the HTTP response body."""
    return _FindBodyStart(resp_text, resp_len)


# ============================================================
# Response parsing (header lookup / chunked decode / unified parse_response)
# ============================================================

def _CIEq(a: char, b: char) -> bool:
    """Case-insensitive char equality (ASCII only)."""
    if a >= 'A' and a <= 'Z': a = char(int(a) - int('A') + int('a'))
    if b >= 'A' and b <= 'Z': b = char(int(b) - int('A') + int('a'))
    return a == b


def header_value(resp: Response*, name: str, out: str, out_size: int) -> int:
    """Look up a response header by name in the raw response (case-insensitive, first value).
    Returns 0 on found+copied; -1 if missing or bad args.
    """
    if resp is None or resp._raw_buf is None or name is None or out is None: return -1
    p: str = resp._raw_buf

    # Skip status line
    while p[0] != '\0' and p[0] != '\n':
        p += 1
    if p[0] == '\n': p += 1

    # Match each header line
    while p[0] != '\0' and p[0] != '\r' and p[0] != '\n':
        h: str = p
        q: str = name
        matched: bool = True
        while q[0] != '\0':
            if h[0] != q[0] and not _CIEq(h[0], q[0]):
                matched = False
                break
            h += 1
            q += 1
        # Allow [spaces]* ':' after name (RFC has none; lenient)
        while h[0] == ' ':
            h += 1
        if matched and h[0] == ':':
            h += 1
            while h[0] == ' ' or h[0] == '\t':
                h += 1
            i: int = 0
            while h[0] != '\0' and h[0] != '\r' and h[0] != '\n' and i < out_size - 1:
                out[i] = h[0]
                i += 1
                h += 1
            out[i] = 0
            return 0
        # Skip to next line
        while p[0] != '\0' and p[0] != '\n':
            p += 1
        if p[0] == '\n': p += 1

    return -1


def _HexVal(ch: char) -> int:
    if ch >= '0' and ch <= '9': return int(ch - '0')
    if ch >= 'a' and ch <= 'f': return int(ch - 'a') + 10
    if ch >= 'A' and ch <= 'F': return int(ch - 'A') + 10
    return -1


def decode_chunked(src: str, src_len: int, dst: str, dst_cap: int) -> int:
    """Decode chunked body per RFC 7230 (chunk-ext ignored, trailer ignored).
    Returns decoded byte count; -1 on failure.
    """
    if src is None or dst is None: return -1

    r: int = 0
    w: int = 0
    while r < src_len:
        # 1) chunk size (hex, optional ;ext)
        size: int = 0
        digit_seen: bool = False
        while r < src_len:
            ch: char = src[r]
            if ch == '\r' or ch == '\n' or ch == ';': break
            hv: int = _HexVal(ch)
            if hv < 0: return -1
            digit_seen = True
            if size > 0x7fffffff: return -1
            size = size * 16 + hv
            r += 1
        if not digit_seen: return -1
        # 2) Skip extension and line end
        while r < src_len and src[r] != '\n':
            r += 1
        if r < src_len and src[r] == '\n': r += 1
        # 3) Terminator chunk
        if size == 0: return w
        # 4) Copy data + skip CRLF
        if w + size > dst_cap: return -1
        for k in range(int(size)):
            dst[w + k] = src[r + k]
        w += size
        r += size
        if r < src_len and src[r] == '\r': r += 1
        if r < src_len and src[r] == '\n': r += 1

    return w


def parse_response(resp: Response*, total: int) -> int:
    """Parse the received raw response into Response fields; chunked Transfer-Encoding decodes
    into _body_owned while _raw_buf is kept. Returns 0 ok; -1 fail (text=None, body_len=0).
    """
    if resp is None or resp._raw_buf is None: return -1
    buf: str = resp._raw_buf
    buf[total] = 0

    _ParseStatusLine(buf, &resp.status_code)
    body_offset: int = _FindBodyStart(buf, total)
    if body_offset < 0 or body_offset >= total:
        resp.text = None
        resp.body_len = 0
        return 0

    # Detect Transfer-Encoding: chunked
    te_buf: [64]char
    chunked: bool = False
    if header_value(resp, "Transfer-Encoding", te_buf, 64) == 0:
        if string.strstr(te_buf, "chunked") is not None:
            chunked = True

    if chunked:
        new_buf: str = _mbuddy.alloc(HTTP_BUFSIZ)
        if new_buf is None:
            resp.text = None
            resp.body_len = 0
            return -1
        dec_len: int = decode_chunked(buf + body_offset, total - body_offset, new_buf, HTTP_BUFSIZ)
        if dec_len < 0:
            _mbuddy.free(new_buf)
            resp.text = None
            resp.body_len = 0
            return -1
        new_buf[dec_len] = 0
        resp._body_owned = new_buf
        resp.text = new_buf
        resp.body_len = dec_len
    else:
        resp.text = buf + body_offset
        resp.body_len = total - body_offset

    # ---- Content-Encoding: gzip decompress (zlib.pyzlib, pure Viper) ----
    ce_buf: [64]char
    if header_value(resp, "Content-Encoding", ce_buf, 64) == 0 \
            and string.strstr(ce_buf, "gzip") is not None \
            and resp.text is not None and resp.body_len > 0:
        src_len2: sizet = sizet(resp.body_len)
        olen2: sizet = 0
        gz_out: bytes = pyzlib.decompress(_mbuddy, bytes(resp.text), src_len2, 15, GZIP_BUFSIZ, &olen2)
        if gz_out is not None:
            old_owned: str = resp._body_owned
            if old_owned is not None:
                _mbuddy.free(old_owned)
            gz_str: str = str(gz_out)
            gz_str[olen2] = 0
            resp._body_owned = gz_str
            resp.text = gz_str
            resp.body_len = int(olen2)
        else:
            # Decompress failed: keep raw body, record diagnostics
            stdio.snprintf(_http_err_store, 512, "gzip decode failed: %s", pyzlib.get_error())

    return 0


# ============================================================
# Public API
# ============================================================

def _HttpGetOnce(url: str) -> Response*:
    """HTTP GET single request (no redirect). Sends Accept-Encoding: gzip."""
    if _mbuddy is None: return None

    resp: Response* = _AllocResponse()
    if resp is None: return None

    if _EnsureSocketInit() != 0:
        release(resp)
        return None

    # Parse URL
    host_buf: [256]char
    path_buf: [1024]char
    port: int = 0

    if _ParseUrl(url, host_buf, 256, path_buf, 1024, &port) != 0:
        release(resp)
        return None

    # Create Socket
    sock = socket.Socket(socket.AF_INET, socket.SOCK_STREAM)
    if sock.fd == socket.INVALID_SOCKET:
        release(resp)
        return None

    if sock.connect(host_buf, port) != 0:
        sock.close()
        release(resp)
        return None

    # Build HTTP request
    req_buf: str = _mbuddy.alloc(HTTP_BUFSIZ)
    if req_buf is None:
        sock.close()
        release(resp)
        return None

    stdio.snprintf(req_buf, HTTP_BUFSIZ,
        "GET %s HTTP/1.1\r\nHost: %s\r\nAccept-Encoding: gzip\r\nConnection: close\r\n\r\n",
        path_buf, host_buf)

    req_len: int = int(string.strlen(req_buf))
    sent: int = sock.send(req_buf, req_len)
    _mbuddy.free(req_buf)

    if sent <= 0:
        sock.close()
        release(resp)
        return None

    # Receive response body
    resp_buf: str = _mbuddy.alloc(HTTP_BUFSIZ)
    if resp_buf is None:
        sock.close()
        release(resp)
        return None

    total: int = 0
    while total < HTTP_BUFSIZ - 1:
        n: int = sock.recv(resp_buf + total, HTTP_BUFSIZ - 1 - total)
        if n <= 0: break
        total += n

    resp_buf[total] = 0
    sock.close()

    resp._raw_buf = resp_buf

    parse_response(resp, total)
    return resp


def _HttpPostOnce(url: str, data: str = None, content_type: str = "application/x-www-form-urlencoded") -> Response*:
    """HTTP POST single request (no redirect). Sends Accept-Encoding: gzip."""
    if _mbuddy is None: return None

    resp: Response* = _AllocResponse()
    if resp is None: return None

    if _EnsureSocketInit() != 0:
        release(resp)
        return None

    # Parse URL
    host_buf: [256]char
    path_buf: [1024]char
    port: int = 0

    if _ParseUrl(url, host_buf, 256, path_buf, 1024, &port) != 0:
        release(resp)
        return None

    body_len: int = int(string.strlen(data)) if data is not None else 0
    ct: str = content_type if content_type is not None else "application/x-www-form-urlencoded"

    # Create Socket
    sock = socket.Socket(socket.AF_INET, socket.SOCK_STREAM)
    if sock.fd == socket.INVALID_SOCKET:
        release(resp)
        return None

    if sock.connect(host_buf, port) != 0:
        sock.close()
        release(resp)
        return None

    # Build HTTP request
    req_buf: str = _mbuddy.alloc(HTTP_BUFSIZ)
    if req_buf is None:
        sock.close()
        release(resp)
        return None

    stdio.snprintf(req_buf, HTTP_BUFSIZ,
        "POST %s HTTP/1.1\r\nHost: %s\r\nContent-Type: %s\r\nContent-Length: %d\r\nAccept-Encoding: gzip\r\nConnection: close\r\n\r\n",
        path_buf, host_buf, ct, body_len)

    hdr_len: int = int(string.strlen(req_buf))

    # Send headers + body
    sent: int = sock.send(req_buf, hdr_len)
    if sent > 0 and body_len > 0 and data is not None:
        sock.send(data, body_len)

    _mbuddy.free(req_buf)

    # Receive response body
    resp_buf: str = _mbuddy.alloc(HTTP_BUFSIZ)
    if resp_buf is None:
        sock.close()
        release(resp)
        return None

    total: int = 0
    while total < HTTP_BUFSIZ - 1:
        n: int = sock.recv(resp_buf + total, HTTP_BUFSIZ - 1 - total)
        if n <= 0: break
        total += n

    resp_buf[total] = 0
    sock.close()

    resp._raw_buf = resp_buf

    parse_response(resp, total)
    return resp


# ============================================================
# Redirect following
# ============================================================

def _ResolveRedirectUrl(base: str, loc: str, out: str, cap: int) -> int:
    """Merge Location into a full URL (absolute / protocol-relative / root-relative), written to out.
    Returns 0 on success; -1 on failure.
    """
    if base is None or loc is None or out is None: return -1
    lb: int = int(string.strlen(loc))
    if string.strncmp(loc, "http://", 7) == 0 or string.strncmp(loc, "https://", 8) == 0:
        if lb >= cap: return -1
        string.strcpy(out, loc)
        return 0
    # Take scheme://authority prefix of base
    q: str = base
    while q[0] != '\0' and q[0] != ':': q += 1
    if q[0] != ':': return -1
    q += 1
    if q[0] != '/': return -1
    q += 1
    if q[0] != '/': return -1
    q += 1
    while q[0] != '\0' and q[0] != '/': q += 1
    prefix_len: int = int(uint64(q) - uint64(base))
    need: int = prefix_len + lb + 2
    if need >= cap: return -1
    for i in range(int(prefix_len)):
        out[i] = base[i]
    if loc[0] == '/':
        j: int = 0
        while loc[j] != '\0':
            out[prefix_len + j] = loc[j]
            j += 1
        out[prefix_len + j] = 0
    else:
        out[prefix_len] = '/'
        j: int = 0
        while loc[j] != '\0':
            out[prefix_len + 1 + j] = loc[j]
            j += 1
        out[prefix_len + 1 + j] = 0
    return 0


def _HttpRedirectLoop(method: str, url: str, data: str, content_type: str) -> Response*:
    """GET/POST with redirect following (http:// chain, max 5 hops)."""
    if _mbuddy is None: return None

    cur: str = _mbuddy.alloc(2048)
    if cur is None: return None
    if int(string.strlen(url)) >= 2047:
        _SetHttpError("url too long")
        _mbuddy.free(cur)
        return None
    string.strcpy(cur, url)

    for hop in range(5):
        resp: Response* = None
        if string.strcmp(method, "POST") == 0:
            resp = _HttpPostOnce(cur, data, content_type)
        else:
            resp = _HttpGetOnce(cur)
        if resp is None:
            _mbuddy.free(cur)
            return None

        code: int = resp.status_code
        if not _IsHttpRedirect(code):
            _mbuddy.free(cur)
            return resp

        loc: str = _mbuddy.alloc(2048)
        if loc is None:
            _mbuddy.free(cur)
            return resp
        if header_value(resp, "Location", loc, 2048) != 0:
            _mbuddy.free(loc)
            _mbuddy.free(cur)
            return resp

        nxt: str = _mbuddy.alloc(2048)
        if nxt is None:
            _mbuddy.free(loc)
            _mbuddy.free(cur)
            return resp
        if _ResolveRedirectUrl(cur, loc, nxt, 2048) != 0:
            _SetHttpError("unresolvable redirect Location")
            release(resp)
            _mbuddy.free(nxt)
            _mbuddy.free(loc)
            _mbuddy.free(cur)
            return None
        if string.strncmp(nxt, "https://", 8) == 0:
            _SetHttpError("redirect to https:// needs requests.https")
            release(resp)
            _mbuddy.free(nxt)
            _mbuddy.free(loc)
            _mbuddy.free(cur)
            return None
        release(resp)
        _mbuddy.free(loc)
        _mbuddy.free(cur)
        cur = nxt

    _SetHttpError("too many redirects")
    _mbuddy.free(cur)
    return None


def _IsHttpRedirect(code: int) -> bool:
    return code >= 300 and code < 400


def get(url: str) -> Response*:
    """HTTP GET (follows 3xx redirects, max 5 hops). Returns Response* or None
    on failure (see last_error()).
    """
    return _HttpRedirectLoop("GET", url, None, None)


def post(url: str, data: str = None, content_type: str = "application/x-www-form-urlencoded") -> Response*:
    """HTTP POST (follows 3xx redirects, max 5 hops)."""
    return _HttpRedirectLoop("POST", url, data, content_type)


def release(resp: Response*):
    """Release Response object and its internal buffers.

    Args:
        resp: The Response object to release
    """
    if resp is None: return
    if _mbuddy is None: return
    if resp._body_owned is not None:
        _mbuddy.free(resp._body_owned)
    if resp._raw_buf is not None:
        _mbuddy.free(resp._raw_buf)
    _mbuddy.free(rawptr(resp))


# ============================================================
# Large-file Range download primitive for requests.download: _DlOnce issues a "Range: bytes=
# start-end" GET (no Accept-Encoding) into dst. Thread-safe (no _mbuddy, own socket). >=0 bytes; -1/-2/-3.
# ============================================================

def _RawHeaderValue(buf: str, total: int, name: str, out: str, out_size: int) -> int:
    """Case-insensitive lookup on raw response header area (0=hit+copied; -1=miss)."""
    if buf is None or name is None or out is None or out_size <= 0:
        return -1
    body: int = _FindBodyStart(buf, total)
    if body < 0:
        body = total
    nl: int = 0
    while nl < body:
        eol: int = nl
        while eol < body and buf[eol] != '\r' and buf[eol] != '\n':
            eol += 1
        if eol > nl:
            k: int = 0
            ok: bool = True
            while name[k] != 0 and nl + k < eol:
                if not _CIEq(buf[nl + k], name[k]):
                    ok = False
                    break
                k += 1
            if ok and name[k] == 0 and nl + k < eol and buf[nl + k] == ':':
                v: int = nl + k + 1
                while v < eol and (buf[v] == ' ' or buf[v] == '\t'):
                    v += 1
                vlen: int = eol - v
                if vlen > out_size - 1:
                    vlen = out_size - 1
                for i in range(int(vlen)):
                    out[i] = buf[v + i]
                out[vlen] = 0
                return 0
        nl = eol
        while nl < body and (buf[nl] == '\r' or buf[nl] == '\n'):
            nl += 1
    return -1


def _StatusRaw(buf: str) -> int:
    """Parse status code from the first line ("HTTP/1.1 206 ...")."""
    if buf is None:
        return 0
    i: int = 0
    while buf[i] == ' ':
        i += 1
    while buf[i] != 0 and buf[i] != ' ':
        i += 1
    while buf[i] == ' ':
        i += 1
    code: int = 0
    while buf[i] >= '0' and buf[i] <= '9':
        code = code * 10 + int(buf[i] - '0')
        i += 1
    return code


def _CLenOf(buf: str, total: int) -> int:
    """Read Content-Length (-1 if absent)."""
    hbuf: [32]char
    if _RawHeaderValue(buf, total, "Content-Length", hbuf, 32) != 0:
        return -1
    v: int = 0
    i: int = 0
    while hbuf[i] >= '0' and hbuf[i] <= '9':
        v = v * 10 + int(hbuf[i] - '0')
        i += 1
    return v


def _CRTotalOf(buf: str, total: int) -> sizet:
    """Parse TOTAL from Content-Range: bytes s-e/TOTAL (0 if not 206 / header absent)."""
    hbuf: [128]char
    if _RawHeaderValue(buf, total, "Content-Range", hbuf, 128) != 0:
        return 0
    p: int = 0
    while hbuf[p] != 0 and hbuf[p] != '/':
        p += 1
    if hbuf[p] == 0:
        return 0
    p += 1
    v: sizet = 0
    while hbuf[p] != 0 and hbuf[p] >= '0' and hbuf[p] <= '9':
        v = v * 10 + sizet(hbuf[p] - '0')
        p += 1
    return v


def _DlOnce(url: str, start: sizet, count: int, dst: str, dst_cap: int,
            out_status: int*, out_loc: str, out_loccap: int,
            out_total: sizet*) -> int:
    """HTTP single Range fetch (thread-safe; see module comment)."""
    if url is None or dst is None or dst_cap <= 0 \
            or out_status is None or out_total is None:
        return -1
    *out_status = 0
    *out_total = 0
    if out_loc is not None and out_loccap > 0:
        out_loc[0] = 0

    if _EnsureSocketInit() != 0:
        _SetHttpError("socket init failed")
        return -3

    host_buf: [256]char
    path_buf: [1024]char
    port: int = 0
    if _ParseUrl(url, host_buf, 256, path_buf, 1024, &port) != 0:
        _SetHttpError("bad http url")
        return -3

    sock = socket.Socket(socket.AF_INET, socket.SOCK_STREAM)
    if sock.fd == socket.INVALID_SOCKET:
        _SetHttpError("socket() failed")
        return -3
    if sock.connect(host_buf, port) != 0:
        _SetHttpError("connect failed")
        sock.close()
        return -3

    req: str = stdlib.malloc(1024)
    if req is None:
        sock.close()
        _SetHttpError("out of memory")
        return -3
    cnt: int = count
    if cnt < 0:
        cnt = 0
    end: sizet = start + sizet(cnt) - 1
    if cnt <= 0:
        end = start
    stdio.snprintf(req, 1024,
        "GET %s HTTP/1.1\r\nHost: %s\r\nRange: bytes=%zu-%zu\r\nConnection: close\r\n\r\n",
        path_buf, host_buf, start, end)
    sent: int = sock.send(req, int(string.strlen(req)))
    stdlib.free(req)
    if sent <= 0:
        sock.close()
        _SetHttpError("send failed")
        return -3

    total: int = 0
    tgt: int = -1
    while total < dst_cap - 1:
        room: int = dst_cap - 1 - total
        if room > 4096:
            room = 4096
        n: int = sock.recv(dst + total, room)
        if n <= 0:
            break
        total += n
        if tgt < 0:
            bo: int = _FindBodyStart(dst, total)
            if bo >= 0:
                cl: int = _CLenOf(dst, total)
                if cl >= 0:
                    tgt = bo + cl
        if tgt >= 0 and total >= tgt:
            break
    sock.close()
    dst[total] = 0

    st: int = _StatusRaw(dst)
    *out_status = st
    if st == 0:
        _SetHttpError("empty response")
        return -3
    if _IsHttpRedirect(st):
        if out_loc is not None and out_loccap > 0:
            if _RawHeaderValue(dst, total, "Location", out_loc, out_loccap) != 0:
                out_loc[0] = 0
        return -2
    if st != 200 and st != 206:
        stdio.snprintf(_http_err_store, 512, "http status %d", st)
        return -3

    if st == 206:
        *out_total = _CRTotalOf(dst, total)
    else:
        cl2: int = _CLenOf(dst, total)
        if cl2 > 0:
            *out_total = sizet(cl2)
    bo: int = _FindBodyStart(dst, total)
    if bo < 0 or bo >= total:
        return 0
    blen: int = total - bo
    if blen > cnt and cnt > 0:
        blen = cnt
    return blen